Generic Name: guanidine (GWAN ih deen)
Brand Names: Guanidine HCl

What is Guanidine HCl (guanidine)?

Guanidine improves the action of a chemical in the body that regulates muscle cells.

Guanidine is used to treat muscle weakness caused by Eaton-Lambert syndrome. Guanidine will not treat myasthenia gravis.

Guanidine may also be used for purposes other than those listed in this medication guide.

What is the most important information I should know about Guanidine HCl (guanidine)?

Before taking this medication, tell your doctor if you have bone marrow depression or a weak immune system.

Take this medication exactly as it was prescribed for you. Do not take the medication in larger amounts, or take it for longer than recommended by your doctor.

Your doctor may occasionally change your dose to make sure you get the best results from this medication.

Guanidine can lower the blood cells that help your body fight infections. This can make it easier for you to bleed from an injury or get sick from being around others who are ill. To be sure your blood cells do not get too low, your blood will need to be tested on a regular basis. Your urine may also need to be tested. It is important that you not miss any scheduled visits to your doctor.

What should I discuss with my health care provider before taking Guanidine HCl (guanidine)?

Before using this medication, tell your doctor if you have:

• bone marrow depression; or

• a weak immune system.

If you have any of these conditions, you may not be able to use guanidine, or you may need a dosage adjustment or special tests during treatment.

This medication may be harmful to an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment. Guanidine can pass into breast milk and may harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.

How should I take Guanidine HCl (guanidine)?

Take this medication exactly as it was prescribed for you. Do not take the medication in larger amounts, or take it for longer than recommended by your doctor.

Your doctor may occasionally change your dose to make sure you get the best results from this medication.

Guanidine can lower the blood cells that help your body fight infections. This can make it easier for you to bleed from an injury or get sick from being around others who are ill. To be sure your blood cells do not get too low, your blood will need to be tested on a regular basis. Your urine may also need to be tested. It is important that you not miss any scheduled visits to your doctor.

Store guanidine at room temperature away from moisture and heat.

What happens if I miss a dose?

Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and take the medicine at the next regularly scheduled time. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention if you think you have used too much of this medicine.

Symptoms of a guanidine overdose may include loss of appetite, diarrhea, numbness or tingling of the lips and fingers, nervousness, tremors, severe muscle spasms or twitching, diarrhea, and vomiting.

What should I avoid while taking Guanidine HCl (guanidine)?

Avoid contact with people who have colds, the flu, or other contagious illnesses. Contact your doctor immediately if you develop signs of infection.

Do not receive a vaccine while you are being treated with guanidine. Vaccines may not work as well during your treatment with guanidine.

Guanidine HCl (guanidine) side effects

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat. Call your doctor at once if you have any of these serious side effects:

• easy bruising or bleeding, unusual weakness;

• fever, chills, body aches, flu symptoms;

• unusual thoughts, changes in behavior;

• feeling light-headed, fainting;

• confusion, hallucinations (seeing things that are not there);

• weakness, lack of coordination;

• numbness, coldness, or tingling in your face, lips, hands, or feet; or

• fast or pounding heartbeats.

Other less serious side effects are more likely to occur, such as:

• nausea, loss of appetite, diarrhea, stomach pain;

• skin rash;

• increased sweating; or

• dry mouth, dry flaky skin.

Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect Guanidine HCl (guanidine)?

Before taking guanidine, tell your doctor if you are using any of the following drugs:

• a steroid medicine;

• cancer chemotherapy or radiation;

• cyclosporine (Neoral, Sandimmune, Gengraf);

• etanercept (Enbrel), efalizumab (Raptiva), tacrolimus (Prograf), sirolimus (Rapamune); or

• any other medicines that can weaken your immune system.

If you are using any of these drugs, you may not be able to use guanidine, or you may need dosage adjustments or special tests during treatment.

There may be other drugs not listed that can affect guanidine. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor.

Where can I get more information?

• Your pharmacist has more information about guanidine written for health professionals that you may read.

• Every effort has been made to ensure that the information provided by Cerner Multum, Inc. (‘Multum’) is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum’s drug information does not endorse drugs, diagnose patients or recommend therapy. Multum’s drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2006 Cerner Multum, Inc. Version: 1.03. Revision Date: 4/12/2009 4:39:56 PM.

Generic Name: Guaifenesin/Phenylephrine (gwye-FEN-e-sin/fen-il-EF-rin)
Brand Name: Examples include Entex LA and Guaphenyl LA

Guaphenyl LA Sustained-Release Capsules are used for:

Relieving congestion, cough, and throat and airway irritation due to colds, flu, or hay fever. It may also be used for other conditions as determined by your doctor.

Guaphenyl LA Sustained-Release Capsules are a decongestant and expectorant combination. It works by constricting blood vessels and shrinking swollen and congested nasal tissues (mucous membranes) and by thinning and loosening mucus in the airway. This allows you to breathe more easily and makes coughs more productive.

Do NOT use Guaphenyl LA Sustained-Release Capsules if:

• you are allergic to any ingredient in Guaphenyl LA Sustained-Release Capsules
• you have severe high blood pressure, severe heart blood vessel disease, rapid heartbeat, or other severe heart problems
• you have taken furazolidone or a monoamine oxidase inhibitor (MAOI) (eg, phenelzine) within the last 14 days

Contact your doctor or health care provider right away if any of these apply to you.

Before using Guaphenyl LA Sustained-Release Capsules:

Some medical conditions may interact with Guaphenyl LA Sustained-Release Capsules. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:

• if you are pregnant, planning to become pregnant, or are breast-feeding
• if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
• if you have allergies to medicines, foods, or other substances
• if you have a fast, slow, or irregular heartbeat
• if you have a history of adrenal gland problems (eg, tumor), heart problems, high blood pressure, diabetes, heart blood vessel problems, stroke, glaucoma, an enlarged prostate, seizures, or an overactive thyroid
• if you have chronic cough

Some MEDICINES MAY INTERACT with Guaphenyl LA Sustained-Release Capsules. Tell your health care provider if you are taking any other medicines, especially any of the following:

• Beta-blockers (eg, propranolol), catechol-O-methyltransferase (COMT) inhibitors (eg, tolcapone), furazolidone, indomethacin, MAOIs (eg, phenelzine), or tricyclic antidepressants (eg, amitriptyline) because they may increase the risk of Guaphenyl LA Sustained-Release Capsules’s side effects
• Digoxin or droxidopa because the risk of irregular heartbeat or heart attack may be increased
• Bromocriptine because the risk of its side effects may be increased by Guaphenyl LA Sustained-Release Capsules
• Guanadrel, guanethidine, mecamylamine, methyldopa, or reserpine because their effectiveness may be decreased by Guaphenyl LA Sustained-Release Capsules

This may not be a complete list of all interactions that may occur. Ask your health care provider if Guaphenyl LA Sustained-Release Capsules may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

How to use Guaphenyl LA Sustained-Release Capsules:

Use Guaphenyl LA Sustained-Release Capsules as directed by your doctor. Check the label on the medicine for exact dosing instructions.

• Take Guaphenyl LA Sustained-Release Capsules by mouth with or without food.
• Take Guaphenyl LA Sustained-Release Capsules with a full glass of water (8 oz/240 mL) unless your doctor directs otherwise.
• Swallow Guaphenyl LA Sustained-Release Capsules whole. Do not break, crush, or chew before swallowing.
• If you miss a dose of Guaphenyl LA Sustained-Release Capsules, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses at once.

Ask your health care provider any questions you may have about how to use Guaphenyl LA Sustained-Release Capsules.

Important safety information:

• Guaphenyl LA Sustained-Release Capsules may cause dizziness. This effect may be worse if you take it with alcohol or certain medicines. Use Guaphenyl LA Sustained-Release Capsules with caution. Do not drive or perform other possibly unsafe tasks until you know how you react to it.
• Do not take diet or appetite control medicines while you are taking Guaphenyl LA Sustained-Release Capsules without checking with your doctor.
• Do NOT take more than the recommended dose or use for longer than prescribed without checking with your doctor.
• If your symptoms do not get better within 5 to 7 days or if they get worse, check with your doctor.
• Guaphenyl LA Sustained-Release Capsules may interfere with certain lab tests. Be sure your doctor and lab personnel know you are taking Guaphenyl LA Sustained-Release Capsules.
• Tell your doctor or dentist that you take Guaphenyl LA Sustained-Release Capsules before you receive any medical or dental care, emergency care, or surgery.
• Use Guaphenyl LA Sustained-Release Capsules with caution in the ELDERLY; they may be more sensitive to its effects.
• Caution is advised when using Guaphenyl LA Sustained-Release Capsules in CHILDREN; they may be more sensitive to its effects.
• PREGNANCY and BREAST-FEEDING: If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using Guaphenyl LA Sustained-Release Capsules while you are pregnant. It is not known if Guaphenyl LA Sustained-Release Capsules are found in breast milk. Do not breast-feed while taking Guaphenyl LA Sustained-Release Capsules.

Possible side effects of Guaphenyl LA Sustained-Release Capsules:

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome:

Dizziness; excitability; headache; nausea; nervousness or anxiety; trouble sleeping; weakness.

Seek medical attention right away if any of these SEVERE side effects occur:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); difficulty urinating; fast or irregular heartbeat; hallucinations; seizures; severe dizziness, lightheadedness, or headache; tremor.

This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088. You may also report side effects at http://www.fda.gov/medwatch.

If OVERDOSE is suspected:

Contact 1-800-222-1222 (the American Association of Poison Control Centers), your local poison control center (http://www.aapcc.org), or emergency room immediately. Symptoms may include blurred vision; confusion; hallucinations; seizures; severe dizziness, lightheadedness, or headache; severe drowsiness; unusually fast, slow, or irregular heartbeat; vomiting.

Proper storage of Guaphenyl LA Sustained-Release Capsules:

Store Guaphenyl LA Sustained-Release Capsules at room temperature, between 59 and 86 degrees F (15 and 30 degrees C). Store away from heat, moisture, and light. Do not store in the bathroom. Keep Guaphenyl LA Sustained-Release Capsules out of the reach of children and away from pets.

General information:

• If you have any questions about Guaphenyl LA Sustained-Release Capsules, please talk with your doctor, pharmacist, or other health care provider.
• Guaphenyl LA Sustained-Release Capsules are to be used only by the patient for whom it is prescribed. Do not share it with other people.
• If your symptoms do not improve or if they become worse, check with your doctor.

This information is a summary only. It does not contain all information about Guaphenyl LA Sustained-Release Capsules. If you have questions about the medicine you are taking or would like more information, check with your doctor, pharmacist, or other health care provider.

Generic Name: guarana (GWAR ah na)
Brand Names:

What is guarana?

The use of guarana in cultural and traditional settings may differ from concepts accepted by current Western medicine. When considering the use of herbal supplements, consultation with a primary health care professional is advisable. Additionally, consultation with a practitioner trained in the uses of herbal/health supplements may be beneficial, and coordination of treatment among all health care providers involved may be advantageous.

Guarana is also known as Paullinia cupana, paullinia, Brazilian cocoa, guarana bread, guarana paste or gum, and zoom. Guarana is also present in some soft drinks imported from South America in a manner similar to American soft-drinks fortified with caffeine.

Guarana contains very high concentrations of caffeine and has been used as a stimulant and appetite suppressant.

Guarana has not been evaluated by the FDA for safety, effectiveness, or purity. All potential risks and/or advantages of guarana may not be known. Additionally, there are no regulated manufacturing standards in place for these compounds. There have been instances where herbal/health supplements have been sold which were contaminated with toxic metals or other drugs. Herbal/health supplements should be purchased from a reliable source to minimize the risk of contamination.

Guarana may also have uses other than those listed in this medication guide.

What is the most important information I should know about guarana?

Guarana, or its active constituent caffeine, should not be taken when formulated with ephedrine in diet aids or performance-enhancing supplements. Potentially fatal irregular heartbeats have been reported to occur.

Guarana has not been evaluated by the FDA for safety, effectiveness, or purity. All potential risks and/or advantages of guarana may not be known. Additionally, there are no regulated manufacturing standards in place for these compounds. There have been instances where herbal/health supplements have been sold which were contaminated with toxic metals or other drugs. Herbal/health supplements should be purchased from a reliable source to minimize the risk of contamination.

Who should not take guarana?

Guarana, or its active constituent caffeine, should not be taken when formulated with ephedrine in diet aids or performance-enhancing supplements. Potentially fatal irregular heartbeats have been reported to occur.

Talk to your doctor or health care provider before taking guarana if you have

• heart problems or high blood pressure,

• kidney disease,

• an overactive thyroid (hyperthyroidism), or

• an anxiety or nervous disorder.

Guarana contains a large amount of caffeine which may be problematic if used by people with any of the conditions listed above. You may not be able to use guarana, or your doctor or health care provider may recommend a lower dose or special monitoring.

Before taking guarana, talk to your doctor, pharmacist, or health care professional if you have allergies (especially to plants), have any medical condition, or if you take other medicines or other herbal/health supplements. Guarana may not be recommended in some situations.

Do not take guarana without first talking to your doctor if you are pregnant or could become pregnant. Guarana contains a large amount of caffeine. Do not take guarana without first talking to your doctor if you are breast-feeding a baby. Guarana contains a large amount of caffeine, which may cause restlessness, sleep disorders, and other effects in breast-feeding infants. There is no information available regarding the use of guarana by children. Guarana contains a large amount of caffeine, which may cause anemia and other problems in children. Do not give any herbal/health supplement to a child without first talking to the child’s doctor.

How should I take guarana?

The use of guarana in cultural and traditional settings may differ from concepts accepted by current Western medicine. When considering the use of herbal supplements, consultation with a primary health care professional is advisable. Additionally, consultation with a practitioner trained in the uses of herbal/health supplements may be beneficial, and coordination of treatment among all health care providers involved may be advantageous.

If you choose to take guarana, use it as directed on the package or as directed by your doctor, pharmacist, or other health care provider.

Standardized formulations of herbal/health supplements may provide a more reliable dose of the product.

Guarana is usually taken as a powder, mixed with water or another beverage.

Store guarana as directed on the package. In general, guarana should be protected from light and moisture.

What happens if I miss a dose?

No information is available regarding a missed dose of guarana. Consult your doctor, pharmacist, or health care professional if you require further information.

What happens if I overdose?

Seek emergency medical attention.

Symptoms of a guarana overdose are not well known but might include painful urination, restlessness, tremor, vomiting, and abdominal spasms.

What should I avoid while taking guarana?

The amount of caffeine consumed in other products should be monitored while taking guarana.

There are no restrictions on food, beverages, or activity while taking guarana, unless otherwise directed by your health care provider.

Guarana side effects

Although rare, serious side effects from guarana have been reported. Stop taking guarana and seek emergency medical attention if you experience

• a serious allergic reaction including difficulty breathing; closing of the throat; swelling of the lips, tongue, or face; or hives; or

• irregular heartbeats or chest pain.

Other less serious side effects may also reported with the use of guarana. Talk to your doctor or health care provider if you experience

• heartburn;

• upset stomach;

• loss of appetite;

• constipation or diarrhea;

• nervousness, irritability, or anxiety;

• sleeplessness;

• irregular heartbeats; or

• headache.

Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.

What other drugs will affect guarana?

Guarana, or its active constituent caffeine, should not be taken when formulated with ephedrine in diet aids or performance-enhancing supplements. Potentially fatal irregular heartbeats have been reported to occur.

Interactions between guarana and other prescription or over-the-counter medicines or herbal/health supplements have not been reported. Talk to your doctor, pharmacist, or health care professional before taking guarana if you are taking any other medicines or supplements.

Where can I get more information?

• Your doctor, pharmacist, or health care provider may have more information about guarana.

• Consultation with a licensed health care professional is advisable before using any herbal/health supplement. Additionally, consultation with a practitioner trained in the uses of herbal/health supplements may be beneficial and coordination of treatment among all health care providers involved may be advantageous. Remember, keep this and all other prescription drug products, over-the-counter drug products, and herbal/health supplements out of the reach of children.
• Every effort has been made to ensure that the information provided by Cerner Multum, Inc. (‘Multum’) is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum’s drug information does not endorse drugs, diagnose patients or recommend therapy. Multum’s drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2006 Cerner Multum, Inc. Version: 1.03. Revision Date: 2/13/04 4:08:18 PM.

Generic Name: Guanfacine (GWAHN-fa-seen)
Brand Name: Intuniv

Guanfacine Extended-Release Tablets are used for:

Treating attention deficit hyperactivity disorder (ADHD).

Guanfacine Extended-Release Tablets are an alpha agonist. Exactly how Guanfacine Extended-Release Tablets works to treat ADHD is not known.

Do NOT use Guanfacine Extended-Release Tablets if:

• you are allergic to any ingredient in Guanfacine Extended-Release Tablets
• you are taking another medicine that contains guanfacine

Contact your doctor or health care provider right away if any of these apply to you.

Before using Guanfacine Extended-Release Tablets:

Some medical conditions may interact with Guanfacine Extended-Release Tablets. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:

• if you are pregnant, planning to become pregnant, or are breast-feeding
• if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
• if you have allergies to medicines, foods, or other substances
• if you have a history of low blood pressure, dizziness when you stand up, heart problems (eg, heart block, slow or irregular heartbeat), or fainting
• if you have liver or kidney problems
• if you are dehydrated or will be exposed to high temperatures
• if you are taking medicine for high blood pressure

Some MEDICINES MAY INTERACT with Guanfacine Extended-Release Tablets. Tell your health care provider if you are taking any other medicines, especially any of the following:

• Tizanidine or medicine for high blood pressure because the risk of low blood pressure or fainting may be increased
• Ketoconazole because it may increase the risk of Guanfacine Extended-Release Tablets’s side effects
• Rifampin because it may decrease Guanfacine Extended-Release Tablets’s effectiveness
• Barbiturates (eg, phenobarbital), benzodiazepines (eg, diazepam), phenothiazines (eg, chlorpromazine), or valproic acid because the risk of their side effects may be increased by Guanfacine Extended-Release Tablets

This may not be a complete list of all interactions that may occur. Ask your health care provider if Guanfacine Extended-Release Tablets may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

How to use Guanfacine Extended-Release Tablets:

Use Guanfacine Extended-Release Tablets as directed by your doctor. Check the label on the medicine for exact dosing instructions.

• An extra patient leaflet is available with Guanfacine Extended-Release Tablets. Talk to your pharmacist if you have questions about this information.
• Take Guanfacine Extended-Release Tablets by mouth with or without food. Do not take it with a high-fat meal.
• Take Guanfacine Extended-Release Tablets with water, milk, or another liquid.
• Swallow Guanfacine Extended-Release Tablets whole. Do not break, crush, or chew before swallowing.
• If you are switching to Guanfacine Extended-Release Tablets from immediate-release guanfacine, talk with your doctor about how you should stop taking the immediate-release tablets and start taking Guanfacine Extended-Release Tablets.
• Do not suddenly stop taking Guanfacine Extended-Release Tablets. You may have an increased risk of side effects. If you need to stop Guanfacine Extended-Release Tablets, your doctor will gradually lower your dose.
• If you miss a dose of Guanfacine Extended-Release Tablets, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses at once. If you miss more than 1 dose, contact your doctor.

Ask your health care provider any questions you may have about how to use Guanfacine Extended-Release Tablets.

Important safety information:

• Guanfacine Extended-Release Tablets may cause drowsiness or dizziness. These effects may be worse if you take it with alcohol or certain medicines. Use Guanfacine Extended-Release Tablets with caution. Do not drive or perform other possibly unsafe tasks until you know how you react to it.
• Guanfacine Extended-Release Tablets may cause dizziness, lightheadedness, or fainting; alcohol, hot weather, exercise, or fever may increase these effects. To prevent them, sit up or stand slowly, especially in the morning. Sit or lie down at the first sign of any of these effects.
• Do not drink alcohol while you are taking Guanfacine Extended-Release Tablets.
• Talk with your doctor before you use medicines that may cause drowsiness (eg, sleep aids, muscle relaxers) while you are using Guanfacine Extended-Release Tablets; it may add to their effects. Ask your pharmacist if you have questions about which medicines may cause drowsiness.
• Do NOT take more than the recommended dose without checking with your doctor.
• Do not become overheated or dehydrated in hot weather or while you are being active; the risk of low blood pressure or fainting may be increased.
• Lab tests, including heart rate and blood pressure, may be performed while you use Guanfacine Extended-Release Tablets. These tests may be used to monitor your condition or check for side effects. Be sure to keep all doctor and lab appointments.
• Guanfacine Extended-Release Tablets should be used with extreme caution in CHILDREN younger than 6 years old; safety and effectiveness in these children have not been confirmed.
• PREGNANCY and BREAST-FEEDING: If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using Guanfacine Extended-Release Tablets while you are pregnant. It is not known if Guanfacine Extended-Release Tablets are found in breast milk. If you are or will be breast-feeding while you use Guanfacine Extended-Release Tablets, check with your doctor. Discuss any possible risks to your baby.

Possible side effects of Guanfacine Extended-Release Tablets:

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome:

Constipation; decreased appetite; dizziness; drowsiness; dry mouth; headache; irritability; nausea; sluggishness; stomach pain; tiredness; vomiting.

Seek medical attention right away if any of these SEVERE side effects occur:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); fainting; severe or persistent dizziness, drowsiness, or weakness; slow or irregular heartbeat.

This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088. You may also report side effects at http://www.fda.gov/medwatch.

If OVERDOSE is suspected:

Contact 1-800-222-1222 (the American Association of Poison Control Centers), your local poison control center ( http://www.aapcc.org), or emergency room immediately. Symptoms may include pinpoint pupils; severe or persistent dizziness, drowsiness, or sluggishness; slow heartbeat.

Proper storage of Guanfacine Extended-Release Tablets:

Store Guanfacine Extended-Release Tablets at room temperature, between 59 and 86 degrees F (15 and 30 degrees C). Store away from heat, moisture, and light. Do not store in the bathroom. Keep Guanfacine Extended-Release Tablets out of the reach of children and away from pets.

General information:

• If you have any questions about Guanfacine Extended-Release Tablets, please talk with your doctor, pharmacist, or other health care provider.
• Guanfacine Extended-Release Tablets are to be used only by the patient for whom it is prescribed. Do not share it with other people.
• If your symptoms do not improve or if they become worse, check with your doctor.

This information is a summary only. It does not contain all information about Guanfacine Extended-Release Tablets. If you have questions about the medicine you are taking or would like more information, check with your doctor, pharmacist, or other health care provider.

Why is Guanfacine hydrochloride prescribed? Guanfacine is given to help control high blood pressure. This medication reduces nerve impulses to the heart and arteries; this slows the heartbeat, relaxes the blood vessels, and thus reduces blood pressure. Guanfacine may be given alone or in combination with other high blood pressure medications, especially thiazide diuretics, such as Diuril, Esidrix, or Naturetin. Most important fact about Guanfacine hydrochloride You must take guanfacine regularly for it to be effective. Since blood pressure declines gradually, it may be several weeks before you get the full benefit of guanfacine; and you must continue taking it even if you are feeling well. Guanfacine does not cure high blood pressure; it merely keeps it under control. How should you take Guanfacine hydrochloride? Take guanfacine exactly as prescribed by your doctor–usually 1 dose per day. Guanfacine should be taken at bedtime, since it will probably cause drowsiness. After 3 or 4 weeks, if your blood pressure is still too high, your doctor may raise the dosage of guanfacine. In some cases, you may take 2 evenly spaced doses per day rather than a single dose at bedtime. –If you miss a dose… Take the forgotten dose as soon as you remember. This will help to keep the proper amount of medicine in your body. However, if it is almost time for the next dose, skip the one you missed and go back to your regular schedule. Never try to “catch up” by doubling the dose. If you miss taking guanfacine for 2 or more days in a row, check with your doctor. –Storage instructions… Store guanfacine at room temperature. Use the container it came in. Guanfacine hydrochloride side effects Side effects cannot be anticipated. If any develop or change in intensity, inform your doctor as soon as possible. Only your doctor can determine whether it is safe for you to continue taking guanfacine. This medication will probably make you drowsy, especially when you first begin to take it. Side effects may include: Constipation, dizziness, dry mouth, fatigue, headache, impotence, sleepiness, weakness Some of these side effects may lessen or disappear as your body gets used to guanfacine. Why should Guanfacine hydrochloride not be prescribed? Do not take guanfacine if you are sensitive to it or have ever had an allergic reaction to it. Guanfacine is not recommended for controlling the severe high blood pressure that accompanies toxemia of pregnancy (a disorder of pregnant women characterized by a rise in blood pressure, swelling, and leakage of protein into urine). Special warnings about Guanfacine hydrochloride While taking guanfacine, you should be monitored very closely by your doctor if you have any of the following medical conditions: Chronic kidney or liver failure Heart disease History of stroke Recent heart attack Since guanfacine causes drowsiness and may also make you dizzy, do not drive, climb, or perform hazardous tasks until you find out exactly how Guanfacine hydrochloride affects you. While taking guanfacine, use alcoholic beverages with care; you may feel intoxicated after drinking only a small amount of alcohol. If you have kidney damage and also take the antiseizure drug phenytoin (Dilantin), your body may process and eliminate guanfacine rather quickly; in that case, you may need fairly frequent doses of guanfacine to lower your blood pressure adequately. If you have been taking guanfacine for a while, do not stop taking it without consulting your doctor. Discontinuing abruptly may result in nervousness, rapid pulse, anxiety, heartbeat irregularities, and so-called rebound high blood pressure (higher than before you started taking guanfacine). If you do have rebound high blood pressure, it will probably develop 2 to 4 days after your last dose of guanfacine. Rebound high blood pressure, if it occurs, will usually diminish and then disappear over a period of 2 to 4 days. Possible food and drug interactions when taking Guanfacine hydrochloride If guanfacine is taken with certain other drugs, the effects of either could be increased, decreased, or altered. It is especially important to check with your doctor before combining guanfacine with the following: Barbiturates such as Amytal, Seconal, Tuinal, and others Benzodiazepines such as Tranxene, Valium, Xanax, and others Phenothiazines such as Mellaril, Stelazine, Thorazine, and others Phenytoin (Dilantin) Special information if you are pregnant or breastfeeding If you are pregnant or plan to become pregnant, notify your doctor immediately. Guanfacine should be taken during pregnancy only if clearly needed. It is not known whether guanfacine appears in breast milk. Check with your doctor if you plan to breastfeed. Recommended dosage for Guanfacine hydrochloride ADULTS The usual recommended dose of guanfacine is 1 milligram daily, taken at bedtime. If necessary, after 3 to 4 weeks your doctor may increase the daily dosage to 2 milligrams. CHILDREN The safety and effectiveness of guanfacine have not been established in children under 12 years of age. Overdosage Any medication taken in excess can have serious consequences. If you suspect an overdose of guanfacine, seek medical attention immediately. Symptoms of guanfacine overdose may include: Drowsiness, lethargy, slowed heartbeat, very low blood pressure

Generic Name: guanethidine (gwha NETH ih deen)
Brand Names: Ismelin

What is guanethidine?

Guanethidine lowers blood pressure by decreasing the levels of certain chemicals in the blood. This allows your blood vessels (veins and arteries) to relax (widen).

Guanethidine is used to treat hypertension (high blood pressure). Guanethidine is also used to treat high blood pressure in the kidneys.

Guanethidine may also be used for purposes other than those listed in this medication guide.

What is the most important information I should know about guanethidine?

Use caution when driving, operating machinery, or performing other hazardous activities. Guanethidine may cause dizziness or drowsiness. If you experience dizziness or drowsiness, avoid these activities.

Use caution when rising from a sitting or lying position, especially first thing in the morning. Dizziness may occur while taking guanethidine and may result in a fall.

Do not stop taking guanethidine suddenly without first talking to your doctor. This could cause severely high blood pressure, nervousness, and anxiety.

Before having surgery, tell your doctor or dentist that you are taking this medication.

What should I discuss with my healthcare provider before taking guanethidine?

You cannot take guanethidine if you

• have pheochromocytoma;

• have congestive heart failure; or

• are taking a monoamine oxidase inhibitor such as isocarboxazid (Marplan), phenelzine (Nardil), or tranylcypromine (Parnate).

Before taking this medication, tell your doctor if you

• have peptic ulcer disease (stomach ulcers) or another stomach disease;

• have gallstones,

• have kidney disease;

• have any type of heart disease;

• have asthma;

• have ulcerative colitis;

• are suffering from depression (especially if you have suicidal thoughts); or

• are receiving electroconvulsive shock therapy.

You may require a dosage adjustment or special monitoring during treatment if you have any of the conditions listed above.

Guanethidine is in the FDA pregnancy category C. This means that it is not known whether guanethidine will be harmful to an unborn baby. Do not take guanethidine without first talking to your doctor if you are pregnant or could become pregnant during treatment. Guanethidine passes into breast milk and may be harmful to a nursing infant. Do not take guanethidine without first talking to your doctor if you are breast-feeding a baby.

How should I take guanethidine?

Take guanethidine exactly as directed. If you do not understand these directions, ask your pharmacist, nurse, or doctor to explain them to you.

Take each dose with a full glass of water. Take guanethidine with food or milk if it causes stomach upset.

It is important to take guanethidine regularly to get the most benefit.

Do not stop taking guanethidine suddenly without first talking to your doctor. This could cause severely high blood pressure, nervousness, and anxiety.

Your doctor may want you to have blood pressure monitoring or other medical evaluations during treatment with guanethidine to monitor progress and side effects.

Store this medication at room temperature away from moisture and heat.

See also: Guanethidine dosage in more detail

What happens if I miss a dose?

Take the missed dose as soon as you remember. However, if it is almost time for the next dose, skip the dose you missed and take only the next regularly scheduled dose. Do not take a double dose of this medication.

What happens if I overdose?

Seek emergency medical attention if an overdose is suspected.

Symptoms of a guanethidine overdose include low blood pressure (fainting, dizziness, weakness); a slow pulse; low body temperature; diarrhea; and slow breathing.

What should I avoid while taking guanethidine?

Use caution when driving, operating machinery, or performing other hazardous activities. Guanethidine may cause dizziness or drowsiness. If you experience dizziness or drowsiness, avoid these activities.

Use caution when rising from a sitting or lying position, especially first thing in the morning. Dizziness may occur while taking guanethidine and may result in a fall.

Avoid alcohol while taking guanethidine. It may increase drowsiness an dizziness caused by guanethidine. Use caution even with small amounts of alcohol.

Guanethidine may increase the effects of other drugs that cause drowsiness, including antidepressants, alcohol, antihistamines, pain relievers, anxiety medicines, seizure medicines, and muscle relaxants. Dangerous sedation, dizziness, or drowsiness may occur if guanethidine is taken with any of these medications. Tell your doctor about all medicines that you are taking, and do not take any medicine without first talking to your doctor.

Avoid becoming overheated in hot weather or during exercise. Also avoid standing for long periods of time and use caution if you have a fever. These situations increase the effects of guanethidine in the body and may cause dizziness.

Before having surgery, tell your doctor or dentist that you are taking this medication.

Guanethidine side effects

If you experience any of the following serious side effects, stop taking guanethidine and seek emergency medical attention or contact your doctor immediately:

• an allergic reaction (difficulty breathing; closing of the throat; swelling of the lips, tongue, or face; or hives);

• irregular heartbeats;

• heart failure (shortness of breath, swelling of ankles or legs, sudden weight gain of 5 pounds or more); or

• chest pain.

Other, less serious side effects are more likely to occur. Continue to take guanethidine and talk to your doctor if you experience

• unusual fatigue or drowsiness;

• dizziness (avoid standing up to quickly and use caution when performing hazardous activities);

• anxiety, depression, or nightmares;

• diarrhea, nausea, or vomiting (take guanethidine with food or milk if it upsets your stomach);

• stuffy nose or a dry mouth (sucking on ice chips or sugarless hard candy may relieve a dry mouth);

• blurred vision;

• weight gain; or

• impotence or difficulty ejaculating.

Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.

Guanethidine Dosing Information

Usual Adult Dose for Hypertension:

Initial dose: 10 mg orally once a day (25 mg to 50 mg if hospitalized).
Maintenance dose: 25 mg to 50 mg orally once a day.

Usual Adult Dose for Hypertensive Emergency:

Loading dose: 25 mg to 50 mg orally 3 times a day at 6 hour intervals over 1 to 3 days. The nighttime dose is omitted.

What other drugs will affect guanethidine?

Do not take guanethidine without first talking to your doctor if you have taken a monoamine oxidase inhibitor (MAOI) such as isocarboxazid (Marplan), phenelzine (Nardil), or tranylcypromine (Parnate) in the last 14 days.

Before taking this medication, tell your doctor if you are taking any of the following medicines:

• haloperidol (Haldol);

• methylphenidate (Ritalin);

• minoxidil (Loniten);

• thiothixene (Navane);

• respiratory medicines such as albuterol (Ventolin, Proventil, Volmax, others), pirbuterol (Maxair), salmeterol (Serevent), and others;

• phenothiazines such as chlorpromazine (Thorazine), prochlorperazine (Compazine), perphenazine (Trilafon), fluphenazine (Prolixin), thioridazine (Mellaril), and others; or

• tricyclic antidepressants such as amitriptyline (Elavil, Endep), imipramine (Tofranil), doxepin (Sinequan), nortriptyline (Pamelor), and others.

You may require special monitoring or a dose adjustment if you are taking any of the medicines listed above.

Drugs other than those listed here may also interact with guanethidine or affect your condition. Talk to your doctor and pharmacist before taking any prescription or over-the-counter medicines, including vitamins, minerals, and herbal products.

Where can I get more information?

• Your pharmacist has additional information about guanethidine written for health professionals that you may read.

What does my medication look like?

Guanethidine is available with a prescription under the brand name Ismelin. Other brand or generic formulations may also be available. Ask your pharmacist any questions you have about this medication, especially if it is new to you.

• Ismelin 10 mg–round, pale-yellow, scored tablets

• Ismelin 25 mg–round, white, scored tablets

• Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.
• Every effort has been made to ensure that the information provided by Cerner Multum, Inc. (‘Multum’) is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum’s drug information does not endorse drugs, diagnose patients or recommend therapy. Multum’s drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2006 Cerner Multum, Inc. Version: 5.02. Revision Date: 2/13/04 3:58:27 PM.

gwahn-ETH-i-deen

Commonly used brand name(s):

In the U.S.

• Ismelin

Available Dosage Forms:

• Tablet

Therapeutic Class: Antihypertensive

Pharmacologic Class: Adrenergic Blocker

Uses For guanethidine

Guanethidine belongs to the general class of medicines called antihypertensives. It is used to treat high blood pressure (hypertension).

High blood pressure adds to the work load of the heart and arteries. If it continues for a long time, the heart and arteries may not function properly. This can damage the blood vessels of the brain, heart, and kidneys, resulting in a stroke, heart failure, or kidney failure. High blood pressure may also increase the risk of heart attacks. These problems may be less likely to occur if blood pressure is controlled.

Guanethidine works by controlling nerve impulses along certain nerve pathways. As a result, it relaxes the blood vessels so that blood passes through them more easily. This helps to lower blood pressure.

Guanethidine is available only with your doctor’s prescription.

Before Using guanethidine

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For guanethidine, the following should be considered:

Allergies

Tell your doctor if you have ever had any unusual or allergic reaction to guanethidine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Pediatric

Although there is no specific information comparing use of guanethidine in children with use in other age groups, guanethidine is not expected to cause different side effects or problems in children than it does in adults.

Geriatric

Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults. Although there is no specific information comparing use of guanethidine in the elderly with use in other age groups, dizziness, lightheadedness, or fainting may be more likely to occur in the elderly, who are more sensitive to the effects of guanethidine.

Pregnancy

	Pregnancy Category	Explanation
All Trimesters	C	Animal studies have shown an adverse effect and there are no adequate studies in pregnant women OR no animal studies have been conducted and there are no adequate studies in pregnant women.

Breast Feeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Interactions with Medicines

Using guanethidine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.

• Brofaromine
• Clorgyline
• Furazolidone
• Iproniazid
• Isocarboxazid
• Lazabemide
• Linezolid
• Moclobemide
• Nialamide
• Pargyline
• Phenelzine
• Procarbazine
• Rasagiline
• Selegiline
• Toloxatone
• Tranylcypromine

Using guanethidine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

• Phenylpropanolamine
• Pseudoephedrine

Using guanethidine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

• Amitriptyline
• Amphetamine
• Doxepin
• Phenylephrine
• Yohimbine

Interactions with Food/Tobacco/Alcohol

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other Medical Problems

The presence of other medical problems may affect the use of guanethidine. Make sure you tell your doctor if you have any other medical problems, especially:

• Asthma (history of) or
• Diarrhea or
• Pheochromocytoma or
• Stomach ulcer (history of)—Guanethidine may worsen these conditions

• Type 2 diabetes mellitus—Effects of medicine used to treat this condition may be increased by guanethidine

• Fever—Effects of guanethidine may be increased

• Heart attack or stroke (recent) or
• Heart or blood vessel disease—Lowering blood pressure may make problems resulting from these conditions worse

• Kidney disease—Guanethidine may worsen this condition. Also, effects of guanethidine may be increased because of slower removal of guanethidine from the body

• Liver disease—Effects of guanethidine may be increased because of slower removal from the body

Proper Use of guanethidine

In addition to the use of the medicine your doctor has prescribed, treatment for your high blood pressure may include weight control and care in the types of foods you eat, especially foods high in sodium. Your doctor will tell you which of these are most important for you. You should check with your doctor before changing your diet.

Many patients who have high blood pressure will not notice any signs of the problem. In fact, many may feel normal. It is very important that you take your medicine exactly as directed and that you keep your appointments with your doctor even if you feel well.

Remember that guanethidine will not cure your high blood pressure but it does help control it. Therefore, you must continue to take it as directed if you expect to lower your blood pressure and keep it down. You may have to take high blood pressure medicine for the rest of your life . If high blood pressure is not treated, it can cause serious problems such as heart failure, blood vessel disease, stroke, or kidney disease.

To help you remember to take your medicine, try to get into the habit of taking it at the same time each day.

Dosing

The dose of guanethidine will be different for different patients. Follow your doctor’s orders or the directions on the label. The following information includes only the average doses of guanethidine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

• For oral dosage form (tablets):
  • For high blood pressure:
    • Adults—At first, 10 or 12.5 milligrams (mg) once a day. Then, your doctor may increase your dose to 25 to 50 mg once a day.
    • Children—The dose is based on body weight and must be determined by your doctor. The usual dose is 200 micrograms (mcg) per kilogram (kg) (90.9 mcg per pound) of body weight a day. Then, your doctor may increase your dose as needed.

Missed Dose

If you miss a dose of guanethidine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Precautions While Using guanethidine

It is important that your doctor check your progress at regular visits to make sure that guanethidine is working properly.

Dizziness, lightheadedness, or fainting may occur, especially when you get up from a lying or sitting position. This is more likely to occur in the morning. Getting up slowly may help. When you get up from lying down, sit on the edge of the bed with your feet dangling for 1 or 2 minutes. Then stand up slowly. If the problem continues or gets worse, check with your doctor.

The dizziness, lightheadedness, or fainting is also more likely to occur if you drink alcohol, stand for long periods of time, exercise, or if the weather is hot. While you are taking guanethidine, be careful in the amount of alcohol you drink. Also, use extra care during exercise or hot weather or if you must stand for long periods of time.

Do not take other medicines unless they have been discussed with your doctor. This especially includes over-the-counter (nonprescription) medicines for appetite control, asthma, colds, cough, hay fever, or sinus problems, since they may tend to increase your blood pressure.

Before having any kind of surgery (including dental surgery) or emergency treatment, tell the medical doctor or dentist in charge that you are taking guanethidine.

Tell your doctor if you get a fever since that may change the amount of medicine you have to take.

Male patients: guanethidine may interfere with ejaculation.

guanethidine Side Effects

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

More common

• Swelling of feet or lower legs

Less common or rare

• Chest pain
• shortness of breath

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

• Diarrhea or increase in bowel movements
• dizziness, lightheadedness, or fainting, especially when getting up from a lying or sitting position
• sexual problems in males
• slow heartbeat
• stuffy nose
• unusual tiredness or weakness

Less common or rare

• Blurred vision
• drooping eyelids
• dryness of mouth
• headache
• loss of hair on scalp
• muscle pain or tremors
• nausea or vomiting
• nighttime urination
• skin rash

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

The information contained in the Thomson Reuters Micromedex products as delivered by Drugs.com is intended as an educational aid only. It is not intended as medical advice for individual conditions or treatment. It is not a substitute for a medical exam, nor does it replace the need for services provided by medical professionals. Talk to your doctor, nurse or pharmacist before taking any prescription or over the counter drugs (including any herbal medicines or supplements) or following any treatment or regimen. Only your doctor, nurse, or pharmacist can provide you with advice on what is safe and effective for you.

The use of the Thomson Reuters Healthcare products is at your sole risk. These products are provided “AS IS” and “as available” for use, without warranties of any kind, either express or implied. Thomson Reuters Healthcare and Drugs.com make no representation or warranty as to the accuracy, reliability, timeliness, usefulness or completeness of any of the information contained in the products. Additionally, THOMSON REUTERS HEALTHCARE MAKES NO REPRESENTATION OR WARRANTIES AS TO THE OPINIONS OR OTHER SERVICE OR DATA YOU MAY ACCESS, DOWNLOAD OR USE AS A RESULT OF USE OF THE THOMSON REUTERS HEALTHCARE PRODUCTS. ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE OR USE ARE HEREBY EXCLUDED. Thomson Reuters Healthcare does not assume any responsibility or risk for your use of the Thomson Reuters Healthcare products.

Generic Name: guanethidine and hydrochlorothiazide (gwhan ETH i deen and hye droe klor oh THYE a zide)
Brand Names: Esimil

What is guanethidine and hydrochlorothiazide?

Guanethidine lowers blood pressure by decreasing the levels of certain chemicals in your blood. This allows your blood vessels (veins and arteries) to relax and your heart to beat more slowly and easily.

Hydrochlorothiazide is a thiazide diuretic (water pill). It helps to lower your blood pressure and decrease edema (swelling) by increasing the amount of salt and water you lose in your urine.

Guanethidine and hydrochlorothiazide is used to treat high blood pressure.

Guanethidine and hydrochlorothiazide may also be used for purposes other than those listed in this medication guide.

What is the most important information I should know about guanethidine and hydrochlorothiazide?

Stand up slowly from a sitting or lying position. Guanethidine and hydrochlorothiazide may make you feel dizzy. Do not stop taking guanethidine and hydrochlorothiazide suddenly. Even if you feel better, you need this medication to control your condition. Stopping suddenly could cause severe high blood pressure, anxiety, and other dangerous side effects.

Tell your doctor and dentist that you are taking this medication before having surgery.

Who should not take guanethidine and hydrochlorothiazide?

Do not take guanethidine and hydrochlorothiazide if you have an allergy to sulfa-based drugs such as sulfa antibiotics. You may have an allergic reaction to hydrochlorothiazide.

You must not take guanethidine and hydrochlorothiazide if you

• have pheochromocytoma;

• have congestive heart failure; or

• are taking a monoamine oxidase inhibitor (MAOI) such as isocarboxazid (Marplan), phenelzine (Nardil), or tranylcypromine (Parnate).

Before taking this medication, tell your doctor if you have

• peptic ulcer disease (stomach ulcers) or other stomach problems,

• ulcerative colitis,

• gallstones,

• kidney or liver disease,

• diabetes,

• gout,

• a collagen vascular disease such as systemic lupus erythematosus,

• high levels of cholesterol or triglyceride (types of fat) in your blood,

• pancreatitis,

• asthma, or

• any type of heart disease.

You may require a lower dose or special monitoring during therapy with guanethidine and hydrochlorothiazide if you have any of these conditions.

Guanethidine and hydrochlorothiazide is in the FDA pregnancy category B. This means that it is not expected to harm an unborn baby. Do not take this medication without first talking to your doctor if you are pregnant. Guanethidine and hydrochlorothiazide passes into breast milk and may harm a nursing infant. Do not take this medication without first talking to your doctor if you are breast-feeding a baby. Guanethidine and hydrochlorothiazide has not been approved for use by children.

How should I take guanethidine and hydrochlorothiazide?

Take guanethidine and hydrochlorothiazide exactly as directed. If you do not understand these directions, ask your pharmacist, nurse, or doctor to explain them to you.

Take each dose with a full glass of water. Take guanethidine and hydrochlorothiazide with food or milk if it upsets your stomach.

Do not stop taking guanethidine and hydrochlorothiazide. Stopping suddenly could make your condition much worse or cause very serious side effects.

Store this medication at room temperature away from moisture and heat.

See also: Guanethidine and hydrochlorothiazide dosage in more detail

What happens if I miss a dose?

Take the missed dose as soon as you remember. However, if it is almost time for your next dose, skip the dose you missed and take only your next regularly scheduled dose. Do not take a double dose of this medication.

What happens if I overdose?

Seek emergency medical attention.

Symptoms of a guanethidine and hydrochlorothiazide overdose include low blood pressure (fainting, dizziness, weakness); sleepiness; uncontrollable hand, leg, or arm movements; a slow pulse; low body temperature; diarrhea; increased urination; vomiting, and slow breathing.

What should I avoid while taking guanethidine and hydrochlorothiazide?

Use caution when rising from a sitting or lying position, especially first thing in the morning. You may become dizzy while taking guanethidine and hydrochlorothiazide, and you may fall and injure yourself if you get up quickly.

Do not let yourself become overheated in hot weather or during exercise, and use caution if you have a fever. These situations increase the effects of guanethidine and hydrochlorothiazide, and you may become very dizzy.

Avoid prolonged exposure to sunlight. Hydrochlorothiazide may increase the sensitivity of your skin to sunlight. Use a sunscreen and wear protective clothing when exposure to the sun is unavoidable. Avoid alcohol while taking guanethidine and hydrochlorothiazide. Alcohol, which will further lower your blood pressure, will also increase the drowsiness caused by guanethidine and hydrochlorothiazide and may increase dizziness. Use caution even with small amounts of alcohol.

Avoid a diet high in salt. Too much salt will cause your body to retain water and will decrease the effects of hydrochlorothiazide.

Do not take any over-the-counter cough, cold, allergy, sleep, or diet medications without first asking your doctor or pharmacist. These products will interfere with your guanethidine and hydrochlorothiazide therapy.

Use caution when you are driving, climbing ladders, or performing other hazardous activities until you know how guanethidine and hydrochlorothiazide affects you. If it makes you dizzy or drowsy, avoid these activities.

Tell your doctor and dentist that you are taking this medication before having surgery.

Guanethidine and hydrochlorothiazide side effects

If you experience any of the following serious side effects, stop taking guanethidine and hydrochlorothiazide and seek emergency medical attention:

• an allergic reaction (difficulty breathing; closing of your throat; swelling of your lips, tongue, or face; or hives);

• a very irregular heartbeat;

• heart failure (shortness of breath, swelling of ankles or legs, sudden weight gain of 5 pounds or more);

• chest pain;

• little or no urine;

• unusual fatigue;

• abnormal bleeding or bruising;

• yellow skin or eyes;

• confusion;

• fainting; or

• uncontrollable hand, arm, or leg movements.

Other, less serious side effects are more likely to occur. Continue to take guanethidine and hydrochlorothiazide and talk to your doctor if you experience

• fatigue or drowsiness;

• dizziness (avoid standing up too quickly and use caution when performing hazardous activities);

• anxiety, depression or nightmares;

• diarrhea, nausea, vomiting, or an acid stomach (take guanethidine and hydrochlorothiazide with food or milk if it upsets your stomach);

• abdominal pain;

• a stuffy nose or a dry mouth (sucking on ice chips or sugarless hard candy may relieve a dry mouth);

• blurred vision;

• tingling or numbness in your arms, legs, hands, or feet;

• excessive urination;

• muscle weakness or cramps;

• increased hunger or thirst;

• weight gain;

• sensitivity to sunlight; or

• impotence or difficulty ejaculating.

Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.

Guanethidine and hydrochlorothiazide Dosing Information

Usual Adult Dose for Hypertension:

Initial dose: 1 tablet orally once a day. Determine dosage by individual titration.
Maintenance dose: May increase to 2 tablets orally once a day.

What other drugs will affect guanethidine and hydrochlorothiazide?

Do not take guanethidine and hydrochlorothiazide if you are taking a monoamine oxidase inhibitor (MAOI), or if you have taken one in the last 14 days. MAOIs, used to treat depression, include isocarboxazid (Marplan), phenelzine (Nardil), and tranylcypromine (Parnate).

Before taking this medication, tell your doctor if you are taking any of the following medicines:

• tricyclic antidepressants such as amitriptyline (Elavil, Endep) or doxepin (Sinequan), which may decrease the effects of guanethidine and hydrochlorothiazide;
• other commonly used tricyclic antidepressants, including amoxapine (Asendin), clomipramine (Anafranil), desipramine (Norpramin), imipramine (Tofranil), nortriptyline (Pamelor), and protriptyline (Vivactil);

• digoxin (Lanoxin) or quinidine (Cardioquin, Quinidex, Quinora, Quinaglute), which will increase the risk of experiencing an irregular heartbeat when taken with guanethidine and hydrochlorothiazide;

• barbiturates such as phenobarbital (Luminal, Solfoton), amobarbital (Amytal), and secobarbital (Seconal), which may cause extreme sleepiness or dizziness if taken with guanethidine and hydrochlorothiazide;

• narcotic pain relievers such as codeine (Tylenol #3, Tylenol #4, others), propoxyphene (Darvon, Darvocet, Wygesic), oxycodone (Percodan, Percocet, Tylox), meperidine (Demerol), morphine (MS Contin, Duramorph, others), and others, which also may cause extreme sleepiness or dizziness if taken with guanethidine and hydrochlorothiazide;

• steroid medications such as hydrocortisone (Hydrocortone, Cortef), prednisone (Deltasone, Orasone), prednisolone (Delta Cortef, Prelone), methylprednisolone (Medrol), betamethasone (Celestone), dexamethasone (Decadron, Hexadrol), and others, which may increase the side effects of hydrochlorothiazide;

• prescription and over-the-counter cough, cold, allergy, diet, and sleeping pills, any of which may contain drugs that increase your blood pressure and heart rate and thus decrease the effects of guanethidine;

• the cholesterol-lowering drugs cholestyramine (Questran) and colestipol (Colestid), which may decrease the effects of hydrochlorothiazide if they are used together;

• nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Motrin, Advil), ketoprofen (Orudis, Orudis, KT, Oruvail), and naproxen (Naprosyn, Anaprox, Aleve), which may also decrease the effects of hydrochlorothiazide;

• other commonly used NSAIDs, including diclofenac (Cataflam, Voltaren), etodolac (Lodine), fenoprofen (Nalfon), flurbiprofen (Ansaid), indomethacin (Indocin), ketorolac (Toradol), mefenamic acid (Ponstel), nabumetone (Relafen), oxaprozin (Daypro), piroxicam (Feldene), sulindac (Clinoril), and tolmetin (Tolectin);

• oral antidiabetic drugs such as Glipizide (Glucotrol), glyburide (Micronase, Glynase, Diabeta), chlorpropamide (Diabinese), tolazamide (Tolinase) and tolbutamide (Orinase), which may not lower your blood sugar as well during therapy with guanethidine and hydrochlorothiazide (your diabetes therapy may have to be adjusted);

• lithium (Lithobid, Eskalith), which should not be taken with hydrochlorothiazide because serious side effects may result; or

• other drugs that also lower blood pressure, including acebutolol (Sectral), atenolol (Tenormin), bisoprolol (Zebeta), carteolol (Cartrol), labetalol (Trandate, Normodyne), propranolol (Inderal), pindolol (Visken), timolol (Blocadren), benazepril (Lotensin), enalapril (Vasotec), captopril (Capoten), fosinopril (Monopril), lisinopril (Prinivil, Zestril), moexipril (Univasc), quinapril (Accupril), ramipril (Altace), amlodipine (Norvasc), bepridil (Vascor), diltiazem (Cardizem, Dilacor), felodipine (Plendil), isradipine (Dynacirc), nicardipine (Cardene), nifedipine (Adalat, Procardia), nimodipine (Nimotop), and verapamil (Calan, Verelan, Isoptin).

Drugs other than those listed here may also interact with guanethidine and hydrochlorothiazide or affect your condition. Talk to your doctor and pharmacist before taking any prescription or over-the-counter medicines.

Where can I get more information?

• Your pharmacist has additional information about guanethidine and hydrochlorothiazide written for health professionals that you may read.

What does my medication look like?

Guanethidine and hydrochlorothiazide is available with a prescription under the brand name Esimil. Other brand or generic formulations may also be available. Ask your pharmacist any questions you have about this medication, especially if it is new to you.

guanethidine/hydrochlorothiazide strengths are as follows:

• Esimil 10 mg/25 mg–round, white scored tablets

• Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.
• Every effort has been made to ensure that the information provided by Cerner Multum, Inc. (‘Multum’) is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum’s drug information does not endorse drugs, diagnose patients or recommend therapy. Multum’s drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2006 Cerner Multum, Inc. Version: 4.03. Revision Date: 2/13/04 4:03:59 PM.

Pronunciation: (gwahn-ETH-ih-deen MAH-no-SULL-fate)
Class: Antiadrenergic, peripherally acting

Trade Names:
Ismelin
- Tablets 10 mg
- Tablets 25 mg

Pharmacology

Interferes with release or distribution of norepinephrine from nerve endings, resulting in reduction in total peripheral resistance and diastolic and systolic BP.

Pharmacokinetics

Metabolism

Converted by the liver to 3 metabolites that are less active than the parent drug.

Elimination

Renal Cl is 56 mL/min. T _{1/ 2} is 1.5 to 8 d. Renal excretion.

Indications and Usage

Treatment of moderate and severe hypertension and renal hypertension, including that secondary to pyelonephritis, renal amyloidosis, and renal artery stenosis.

Unlabeled Uses

Reflex sympathetic dystrophy and causalgia.

Contraindications

Known or suspected pheochromocytoma; frank CHF not related to hypertension; use of MAOIs.

Dosage and Administration

Adults Ambulatory

PO 10 mg every day initially; may increase by about 10 mg at 5 to 7 days; increase only if no decrease in standing BP is observed. Maintenance dose: 25 to 50 mg every day.

Hospitalized

PO 25 to 50 mg initially; increase by 25 or 50 mg/day or every other day until desired response is obtained. Loading dose (for severe hypertension): Give at 6 h intervals over 1 to 3 days, omitting nighttime dose.

Children

PO 0.2 mg/kg/24 h (6 mg/m ² /24 h) as single oral dose initially; increase by increment of 0.2 mg/kg/24 h every 7 to 10 days. Max: 3 mg/kg/24 h.

Storage/Stability

Store in tightly closed container at room temperature.

Drug Interactions

Anorexiants

May reverse hypotensive effect of drug.

MAOIs

May decrease effectiveness of guanethidine; discontinue MAOIs more than 1 wk before starting guanethidine therapy.

Phenothiazines

May inhibit hypotensive effect.

Sympathomimetics (eg, ephedrine, epinephrine)

May reverse hypotensive effect of guanethidine; guanethidine may potentiate effects of sympathomimetics.

Tricyclic antidepressants

May inhibit hypotensive effect of drug.

Laboratory Test Interactions

None well documented.

Adverse Reactions

Cardiovascular

Bradycardia; orthostatic fluid retention; edema; angina.

CNS

Dizziness; weakness; lassitude; syncope; fatigue; muscle tremor; mental depression; chest paresthesias; ptosis; headache; confusion.

EENT

Blurred vision; nasal congestion.

GI

Nausea; vomiting; dry mouth; parotid tenderness; diarrhea (may be severe, requiring discontinuation of therapy); increase in bowel movements.

Genitourinary

Inhibition of ejaculation; nocturia; urinary incontinence; priapism.

Hematologic

Anemia; thrombocytopenia.

Respiratory

Dyspnea; asthma in susceptible individuals.

Miscellaneous

Myalgia; weight gain; dermatitis; scalp hair loss; leg cramps.

Precautions

Pregnancy

Category C .

Lactation

Excreted in breast milk.

Children

Safety and efficacy not established.

Elderly

More prone to side reactions of guanethidine therapy, especially orthostatic hypotension.

Renal Function

Use very cautiously, because hypotension may worsen renal function impairment.

Bronchial asthma

May aggravate the hypersensitive condition of asthmatics because of further catecholamine depletion.

Cardiovascular disease

Use cautiously in patients with coronary disease, recent MI, or cerebral vascular disease, especially with encephalopathy; avoid use in patients with severe cardiac failure.

Fever

May decrease dosage requirements.

Orthostatic hypotension

Occurs frequently, especially during initial treatment and with postural changes.

Peptic ulcer

Ulcers may be aggravated by relative increase in parasympathetic tone.

Preoperative withdrawal

Withdrawal is recommended 2 wk prior to surgery to reduce risk of vascular collapse and cardiac arrest during anesthesia; during emergency surgery administer preanesthetic and anesthetic agents cautiously in reduced dosages and prepare for possible vascular collapse.

Overdosage

Symptoms

Severe drowsiness, hypotension, bradycardia, severe diarrhea, nausea, vomiting, syncope.

Patient Information

• Instruct patient in proper technique for taking BP. Advise patient to check BP weekly.
• Caution patient not to get out of bed without help during period of dosage adjustment.
• Advise patient to lie down if dizziness or blurred vision occurs.
• Warn patient not to double up on doses.
• Instruct patient not to discontinue drug abruptly and not to stop taking drug because of improvement in symptoms.
• Counsel patient about benefits of weight reduction, exercise, reduction of alcohol and sodium intake, and cessation of smoking.
• Explain that impotence and ejaculation disturbances may occur but is reversible. Tell patient to report to health care provider.
• Instruct patient to report these symptoms to health care provider: dizziness, diarrhea, confusion, depression, fever, sore throat.
• Caution patient to avoid sudden position changes to avoid orthostatic hypotension.
• Instruct patient to avoid intake of alcoholic beverages or other CNS depressants.
• Advise patient that drug may cause drowsiness and to use caution while driving or performing other tasks requiring mental alertness.

Copyright © 2009 Wolters Kluwer Health.

Generic Name: guanfacine (GWAHN fa seen)
Brand Names: Intuniv, Tenex

What is guanfacine?

Guanfacine reduces nerve impulses in your heart and blood vessels. Guanfacine works by relaxing blood vessels, which lowers blood pressure and improves blood flow.

Guanfacine is used to treat high blood pressure (hypertension). It is sometimes given together with other blood pressure medications.

Guanfacine is also used to treat attention deficit hyperactivity disorder (ADHD) in children who are at least 6 years old.

Guanfacine may also be used for other purposes not listed in this medication guide.

What is the most important information I should know about guanfacine?

You should not use this medication if you are allergic to guanfacine.

Before you take guanfacine, tell your doctor if you have heart disease, heart block, coronary artery disease or a history of stroke, low blood pressure, kidney or liver disease, or if you have recently had a heart attack.

Guanfacine can cause side effects that may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be awake and alert.

Avoid becoming overheated or dehydrated during exercise and in hot weather. Avoid drinking alcohol.

To be sure this medication is helping your condition and not causing harmful effects, your doctor will need to check your progress on a regular basis. Your blood pressure and heart rate may also need to be checked. Do not miss any follow-up visits to your doctor.

If you are being treated for high blood pressure, keep using this medication even if you feel fine. High blood pressure often has no symptoms. You may need to use blood pressure medication for the rest of your life.

Tell your doctor if you regularly use other medicines that make you sleepy. They can add to sleepiness caused by guanfacine.

What should I discuss with my healthcare provider before taking guanfacine?

You should not use this medication if you are allergic to guanfacine.

If you have any of these other conditions, you may need a dose adjustment or special tests to safely use this medication:

• heart disease or heart block;

• coronary artery disease or a history of stroke;

• low blood pressure;

• kidney disease;
• liver disease; or

• if you have recently had a heart attack.

FDA pregnancy category B. This medication is not expected to be harmful to an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment. It is not known whether guanfacine passes into breast milk or if it could harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.

How should I take guanfacine?

Take this medication exactly as prescribed by your doctor. Do not take it in larger amounts or for longer than recommended. Follow the directions on your prescription label.

Your doctor may occasionally change your dose to make sure you get the best results from this medication.

If you take Intuiv to treat ADHD, take your dose in the morning.

If you take Tenex to treat hypertension, you may need to take your dose at bedtime if guanfacine causes severe drowsiness. Follow your doctor’s instructions.

Do not crush, chew, or break an Intuiv extended-release tablet. Swallow the pill whole. Breaking the pill may cause too much of the drug to be released at one time.

If there are any changes in the brand, strength, or type of guanfacine you use, your dosage needs may change. Always check your refills to make sure you have received the correct brand and type of medicine prescribed by your doctor. Ask the pharmacist if you have any questions about the medicine you receive at the pharmacy.

To be sure this medication is helping your condition and not causing harmful effects, your doctor will need to check your progress on a regular basis. Your blood pressure and heart rate may also need to be checked. Do not miss any follow-up visits to your doctor.

Do not stop taking this medication without first talking to your doctor. If you stop taking guanfacine suddenly, your condition may become worse and you could have unpleasant symptoms.

If you are being treated for high blood pressure, keep using this medication even if you feel fine. High blood pressure often has no symptoms. You may need to use blood pressure medication for the rest of your life.

Store this medication at room temperature away from moisture, heat, and light.

See also: Guanfacine dosage in more detail

What happens if I miss a dose?

Take the missed dose as soon as you remember. If it is almost time for your next dose, wait until then to take the medicine and skip the missed dose. Do not take extra medicine to make up the missed dose.

Call your doctor for instructions if you miss more than 2 doses in a row.

What happens if I overdose?

Seek emergency medical attention if you think you have used too much of this medicine.

Overdose symptoms may include drowsiness, dizziness, slow heart rate, or feeling like you might pass out.

What should I avoid while taking guanfacine?

Avoid taking guanfacine with a high-fat meal.

Guanfacine can cause side effects that may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be awake and alert.

Avoid becoming overheated or dehydrated during exercise and in hot weather while you are taking guanfacine.

Avoid drinking alcohol. It can increase some of the side effects of guanfacine.

Guanfacine side effects

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat. Call your doctor at once if you have a serious side effect such as:

• fast or slow heart rate;

• pounding heartbeats, chest tightness;

• numbness or tingling; or

• feeling like you might pass out.

Less serious side effects may include:

• drowsiness, dizziness, tired feeling;

• dry mouth;

• constipation;

• stomach pain;

• weight gain;

• headache; or

• feeling irritable.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Guanfacine Dosing Information

Usual Adult Dose for Hypertension:

Initial dose: 1 mg orally once a day at bedtime, when given alone or in combination with another antihypertensive drug.
Maintenance dose: 1 to 3 mg orally once a day at bedtime.

Usual Pediatric Dose for Attention Deficit Disorder:

Only the guanfacine extended-release formulation is indicated for ADHD.

Children 6 to 17 years of age:

Initial dose: 1 mg extended-release orally once a day in the morning

Dosage should be adjusted in increments of no more than 1 mg/week.

Maintenance dose: 1 to 4 mg extended-release orally once daily in the morning, depending on clinical response and tolerability.

What other drugs will affect guanfacine?

Before you take guanfacine, tell your doctor if you regularly use other medicines that make you sleepy (such as cold or allergy medicine, sedatives, narcotic pain medicine, sleeping pills, muscle relaxers, and medicine for seizures, depression, anxiety, or psychiatric disorders). They can add to sleepiness caused by guanfacine.

Tell your doctor about all other medications you use, especially any other blood pressure medications, or:

• bosentan (Tracleer);

• conivaptan (Vaprisol);

• dexamethasone (Decadron, Hexadrol);

• diclofenac (Arthrotec, Cataflam, Voltaren, Flector Patch, Solareze);

• St. John’s wort;

• imatinib (Gleevec);

• isoniazid (for treating tuberculosis);

• valproic acid (Depakene, Stavzor);

• an antibiotic such as clarithromycin (Biaxin), dalfopristin/quinupristin (Synercid), erythromycin (E.E.S., EryPed, Ery-Tab, Erythrocin), rifampin (Rifadin, Rifater, Rifamate), or telithromycin (Ketek);

• antifungal medication such as clotrimazole (Mycelex Troche), itraconazole (Sporanox), ketoconazole (Nizoral), or voriconazole (Vfend);

• an antidepressant such as nefazodone;

• a barbiturate such as butabarbital (Butisol), secobarbital (Seconal), pentobarbital (Nembutal), or phenobarbital (Solfoton);

• a calcium channel blocker such as diltiazem (Cartia, Cardizem), felodipine (Plendil), nifedipine (Nifedical, Procardia), verapamil (Calan, Covera, Isoptin, Verelan), and others;

• HIV or AIDS medicine such as atazanavir (Reyataz), delavirdine (Rescriptor), efavirenz (Sustiva), etravirine (Intelence), fosamprenavir (Lexiva), indinavir (Crixivan), nelfinavir (Viracept), nevirapine (Viramune), saquinavir (Invirase), or ritonavir (Norvir); or

• seizure medication such as carbamazepine (Carbatrol, Tegretol), felbamate (Felbatol), oxcarbazepine (Trileptal), phenytoin (Dilantin), or primidone (Mysoline).

This list is not complete and there may be other drugs that can interact with guanfacine. Tell your doctor about all your prescription and over-the-counter medications, vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start a new medication without telling your doctor.

Where can I get more information?

• Your pharmacist can provide more information about guanfacine.

• Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.
• Every effort has been made to ensure that the information provided by Cerner Multum, Inc. (‘Multum’) is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum’s drug information does not endorse drugs, diagnose patients or recommend therapy. Multum’s drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2006 Cerner Multum, Inc. Version: 6.01. Revision Date: 11/10/2009 4:24:29 PM.