Dosage Form: injection

Azithromycin for Injection

For I.V. infusion only

ADD-Vantage® Vial

Rx only

To reduce the development of drug-resistant bacteria and maintain the effectiveness of Azithromycin for Injection and other bacterial drugs, Azithromycin for Injection should be used only to treat or prevent infections that are proven or strongly suspected to be caused by bacteria.

Azithromycin Injection Description

Azithromycin for Injection contains the active ingredient azithromycin, an azalide, a subclass of macrolide antibiotics, for intravenous injection. Azithromycin has the chemical name (2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-13-[(2,6-dideoxy-3-C-methyl-3-O-methyl-α-L-ribo - hexopyranosyl)oxy] – 2 – ethyl – 3,4,10 – trihydroxy – 3,5,6,8,10,12,14 – hepta – methyl – 11 – [[3,4,6 - trideoxy - 3 - (dimethylamino) - β - D - xylo - hexopyranosyl]oxy] – 1 – oxa – 6 – azacyclopentadecan – 15 – one. Azithromycin is derived from erythromycin; however, it differs chemically from erythromycin in that a methyl-substituted nitrogen atom is incorporated into the lactone ring. Its molecular formula is C38H72N2O12, and its molecular weight is 749.0.Azithromycin has the following structural formula:

Azithromycin, as the monohydrate, is a white crystalline powder with a molecular formula of C38H72N2O12 • H2O and a molecular weight of 767.0.

Azithromycin for Injection consists of azithromycin monohydrate and the following inactive ingredients: citric acid and sodium hydroxide. Azithromycin for Injection is supplied in lyophilized form in an ADD-Vantage® vial for intravenous administration only after reconstitution, according to directions in the DOSAGE AND ADMINISTRATION section. Each ADD-Vantage® vial contains azithromycin monohydrate equivalent to 500 mg azithromycin, 392 mg citric acid and sodium hydroxide for pH adjustment.

Azithromycin Injection – Clinical Pharmacology

Pharmacokinetics

In patients hospitalized with community-acquired pneumonia receiving single daily one-hour intravenous infusions for 2 to 5 days of 500 mg azithromycin at a concentration of 2 mg/mL, the mean Cmax ± S.D. achieved was 3.63 ± 1.60 mcg/mL, while the 24-hour trough level was 0.20 ± 0.15 mcg/mL, and the AUC24 was 9.60 ± 4.80 mcg•h/mL.

The mean Cmax, 24-hour trough and AUC24 values were 1.14 ± 0.14 mcg/mL, 0.18 ± 0.02 mcg/mL, and 8.03 ±0.86 mcg•h/mL, respectively, in normal volunteers receiving a 3-hour intravenous infusion of 500 mg azithromycin at a concentration of 1 mg/mL. Similar pharmacokinetic values were obtained in patients hospitalized with community-acquired pneumonia that received the same 3-hour dosage regimen for 2-5 days.

The average CLt and Vd values were 10.18 mL/min/kg and 33.3 L/kg, respectively, in 18 normal volunteers receiving 1000 to 4000-mg doses given as 1 mg/mL over 2 hours.

Comparison of the plasma pharmacokinetic parameters following the 1st and 5th daily doses of 500 mg intravenous azithromycin showed only an 8% increase in Cmax but a 61% increase in AUC24 reflecting a threefold rise in C24 trough levels.

Following single oral doses of 500 mg azithromycin (two 250 mg capsules) to 12 healthy volunteers, Cmax, trough level, and AUC24 were reported to be 0.41 mcg/mL, 0.05 mcg/mL, and 2.6 mcg•h/mL, respectively. These oral values are approximately 38%, 83%, and 52% of the values observed following a single 500-mg I.V. 3-hour infusion (Cmax: 1.08 mcg/mL, trough: 0.06 mcg/mL, and AUC24: 5 mcg•h/mL). Thus, plasma concentrations are higher following the intravenous regimen throughout the 24-hour interval. The pharmacokinetic parameters on day 5 of azithromycin 250-mg capsules following a 500-mg oral loading dose to healthy young adults (age 18-40 years old) were as follows: Cmax: 0.24 mcg/mL, AUC24: 2.1 mcg•h/mL. Azithromycin 250 mg capsules are no longer commercially available. Azithromycin 250 mg tablets are bioequivalent to 250 mg capsules in the fasting state.

Median azithromycin exposure (AUC0-288) in mononuclear (MN) and polymorphonuclear (PMN) leukocytes following 1,500 mg of oral azithromycin, administered in single daily doses over either 5 days (two 250 mg tablets on day 1, followed by one 250 mg tablet on days 2-5) or 3 days (500 mg per day for days 1-3) to 12 healthy volunteers, was more than a 1000-fold and 800-fold greater than in serum, respectively.

Distribution

The serum protein binding of azithromycin is variable in the concentration range approximating human exposure, decreasing from 51% at 0.02 mcg/mL to 7% at 2 mcg/mL.

Tissue concentrations have not been obtained following intravenous infusions of azithromycin. Selected tissue (or fluid) concentration and tissue (or fluid) to plasma/serum concentration ratios following oral administration of azithromycin are shown in the following table:

Tissue levels were determined following a single oral dose of 500 mg azithromycin in 7 gynecological patients. Approximately 17 hours after dosing, azithromycin concentrations were 2.7 mcg/g in ovarian tissue, 3.5 mcg/g in uterine tissue, and 3.3 mcg/g in salpinx. Following a regimen of 500 mg on the first day followed by 250 mg daily for 4 days, concentrations in the cerebrospinal fluid were less than 0.01 mcg/mL in the presence of non-inflamed meninges.

Metabolism

In vitro and in vivo studies to assess the metabolism of azithromycin have not been performed.

Elimination

Plasma concentrations of azithromycin following single 500 mg oral and Intravenous doses declined in a polyphasic pattern with a mean apparent plasma clearance of 630 mL/min and terminal elimination half-life of 68 hours. The prolonged terminal half-life is thought to be due to extensive uptake and subsequent release of drug from tissues.

In a multiple-dose study in 12 normal volunteers utilizing a 500-mg (1 mg/mL) one-hour intravenous-dosage regimen for five days, the amount of administered azithromycin dose excreted in urine in 24 hours was about 11% after the 1st dose and 14% after the 5th dose. These values are greater than the reported 6% excreted unchanged in urine after oral administration of azithromycin. Biliary excretion is a major route of elimination for unchanged drug, following oral administration.

Special Populations

Renal Insufficiency

Azithromycin pharmacokinetics were investigated in 42 adults (21 to 85 years of age) with varying degrees of renal impairment. Following the oral administration of a single 1,000 mg dose of azithromycin, mean Cmax and AUC0-120 increased by 5.1% and 4.2%, respectively in subjects with mild to moderate renal impairment (GFR 10 to 80 mL/min) compared to subjects with normal renal function (GFR >80 mL/min). The mean Cmax and AUC0-120 increased 61% and 35%, respectively in subjects with severe renal impairment (GFR <10 mL/min) compared to subjects with normal renal function (GFR >80 mL/min). (See DOSAGE AND ADMINISTRATION.)

Hepatic Insufficiency

The pharmacokinetics of azithromycin in subjects with hepatic impairment have not been established.

Gender

There are no significant differences in the disposition of azithromycin between male and female subjects. No dosage adjustment is recommended based on gender.

Geriatric Patients

Pharmacokinetic studies with intravenous azithromycin have not been performed in older volunteers. Pharmacokinetics of azithromycin following oral administration in older volunteers (65-85 years old) were similar to those in younger volunteers (18-40 years old) for the 5-day therapeutic regimen.

Pediatric Patients

Pharmacokinetic studies with intravenous azithromycin have not been performed in children.

Drug-Drug Interactions

Drug interaction studies were performed with oral azithromycin and other drugs likely to be co-administered. The effects of co-administration of azithromycin on the pharmacokinetics of other drugs are shown in Table 3 and the effect of other drugs on the pharmacokinetics of azithromycin are shown in Table 4.

Co-administration of azithromycin at therapeutic doses had a modest effect on the pharmacokinetics of the drugs listed in Table 3. No dosage adjustment of drugs listed in Table 3 is recommended when co-administered with azithromycin.

Co-administration of azithromycin with efavirenz or fluconazole had a modest effect on the pharmacokinetics of azithromycin. Nelfinavir significantly increased the Cmax and AUC of azithromycin. No dosage adjustment of azithromycin is recommended when administered with drugs listed in Table 4. (See PRECAUTIONS - Drug Interactions.)

Microbiology Azithromycin acts by binding to the 50S ribosomal subunit of susceptible microorganisms and, thus, interfering with microbial protein synthesis. Nucleic acid synthesis is not affected.

Azithromycin concentrates in phagocytes and fibroblasts as demonstrated by in vitro incubation techniques. Using such methodology, the ratio of intracellular to extracellular concentration was >30 after one hour incubation. In vivo studies suggest that concentration in phagocytes may contribute to drug distribution to inflamed tissues.

Azithromycin has been shown to be active against most isolates of the following microorganisms, both in vitro and in clinical infections as described in the INDICATIONS AND USAGE section of the package insert for Azithromycin for Injection.

Aerobic and facultative Gram-positive microorganisms

Staphylococcus aureus

Streptococcus pneumoniae

NOTE: Azithromycin demonstrates cross-resistance with erythromycin-resistant gram-positive strains. Most strains of Enterococcus faecalis and methicillin-resistant-staphylococci are resistant to azithromycin.

Aerobic and facultative Gram-negative microorganisms

Haemophilus influenzae

Moraxella catarrhalis

Neisseria gonorrhoeae

“Other” microorganisms

Chlamydia pneumoniae

Chlamydia trachomatis

Legionella pneumophila

Mycoplasma hominis

Mycoplasma pneumoniae

Beta-lactamase production should have no effect on azithromycin activity.

Azithromycin has been shown to be active against most strains of the following microorganisms, both in vitro and in clinical infections as described in the INDICATIONS AND USAGE section of the package insert for azithromycin tablets and azithromycin for oral suspension.

Aerobic and facultative Gram-positive microorganisms

Staphylococcus aureus

Streptococcus agalactiae

Streptococcus pneumoniae

Streptococcus pyogenes

Aerobic and facultative Gram-negative microorganisms

Haemophilus ducreyi

Haemophilus influenzae

Moraxella catarrhalis

Neisseria gonorrhoeae

“Other” microorganisms

Chlamydia pneumoniae

Chlamydia trachomatis

Mycoplasma pneumoniae

Beta-lactamase production should have no effect on azithromycin activity.

The following in vitro data are available, but their clinical significance is unknown.

At least 90% of the following microorganisms exhibit an in vitro minimum inhibitory concentration (MIC) less than or equal to the susceptible breakpoints for azithromycin. However, the safety and effectiveness of azithromycin in treating clinical infections due to these microorganisms have not been established in adequate and well-controlled clinical trials.

Aerobic and facultative Gram-positive microorganisms

Streptococci (Groups C, F, G)

Viridans group streptococci

Aerobic and facultative Gram-negative microorganisms

Bordetella pertussis

Anaerobic microorganisms

Peptostreptococcus species

Prevotella bivia

“Other” microorganisms

Ureaplasma urealyticum

Beta-lactamase production should have no effect on azithromycin activity.

Susceptibility Testing Methods:

When available, the results of in vitro susceptibility test results for antimicrobial drugs used in resident hospitals should be provided to the physician as periodic reports which describe the susceptibility profile of nosocomial and community-acquired pathogens. These reports may differ from susceptibility data obtained from outpatient use, but could aid the physician in selecting the most effective antimicrobial.

Dilution techniques:

Quantitative methods are used to determine antimicrobial minimum inhibitory concentrations (MICs). These MICs provide estimates of the susceptibility of bacteria to antimicrobial compounds. The MICs should be determined using a standardized procedure. Standardized procedures are based on a dilution method1,3 (broth or agar) or equivalent with standardized inoculum concentrations and standardized concentrations of azithromycin powder. The MIC values should be interpreted according to criteria provided in Table 5.

Diffusion techniques:

Quantitative methods that require measurement of zone diameters also provide reproducible estimates of the susceptibility of bacteria to antimicrobial compounds. One such standardized procedure2,3 requires the use of standardized inoculum concentrations. This procedure uses paper disks impregnated with 15-mcg azithromycin to test the susceptibility of microorganisms to azithromycin. The disk diffusion interpretive criteria are provided in Table 5.

A report of “susceptible” indicates that the pathogen is likely to be inhibited if the antimicrobial compound reaches the concentrations usually achievable. A report of “intermediate” indicates that the result should be considered equivocal, and, if the microorganism is not fully susceptible to alternative, clinically feasible drugs, the test should be repeated. This category implies possible clinical applicability in body sites where the drug is physiologically concentrated or in situations where high dosage of drug can be used. This category also provides a buffer zone which prevents small uncontrolled technical factors from causing major discrepancies in interpretation. A report of “resistant” indicates that the pathogen is not likely to be inhibited if the antimicrobial compound reaches the concentrations usually achievable; other therapy should be selected.

QUALITY CONTROL

Standardized susceptibility test procedures require the use of quality control microorganisms to control the technical aspects of the test procedures. Standard azithromycin powder should provide the following range of values noted in Table 6. Quality control microorganisms are specific strains of organisms with intrinsic biological properties. QC strains are very stable strains which will give a standard and repeatable susceptibility pattern. The specific strains used for microbiological quality control are not clinically significant.

Indications and Usage for Azithromycin Injection

Azithromycin for Injection is indicated for the treatment of patients with infections caused by susceptible strains of the designated microorganisms in the conditions listed below. As recommended dosages, durations of therapy, and applicable patient populations vary among these infections, please see DOSAGE AND ADMINISTRATION for dosing recommendations with the ADD-Vantage diluent container.

Community-acquired pneumonia due to Chlamydia pneumoniae, Haemophilus influenzae, Legionella pneumophila, Moraxella catarrhalis, Mycoplasma pneumoniae, Staphylococcus aureus, or Streptococcus pneumoniae in patients who require initial intravenous therapy.

Pelvic inflammatory disease due to Chlamydia trachomatis, Neisseria gonorrhoeae, or Mycoplasma hominis in patients who require initial intravenous therapy. If anaerobic microorganisms are suspected of contributing to the infection, an antimicrobial agent with anaerobic activity should be administered in combination with azithromycin.

Azithromycin for Injection should be followed by azithromycin by the oral route as required. (See DOSAGE AND ADMINISTRATION.)

Appropriate culture and susceptibility tests should be performed before treatment to determine the causative microorganism and its susceptibility to azithromycin. Therapy with Azithromycin for Injection may be initiated before results of these tests are known; once the results become available, antimicrobial therapy should be adjusted accordingly.

To reduce the development of drug-resistant bacteria and maintain the effectiveness of Azithromycin for Injection and other antibacterial drugs, Azithromycin for Injection should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.

Contraindications

Azithromycin for Injection is contraindicated in patients with known hypersensitivity to azithromycin, erythromycin, any macrolide or ketolide antibiotic.

Warnings

Serious allergic reactions, including angioedema, anaphylaxis, and dermatologic reactions including Stevens Johnson Syndrome and toxic epidermal necrolysis have been reported rarely in patients on azithromycin therapy. Although rare, fatalities have been reported. (See CONTRAINDICATIONS.) Despite initially successful symptomatic treatment of the allergic symptoms, when symptomatic therapy was discontinued, the allergic symptoms recurred soon thereafter in some patients without further azithromycin exposure. These patients required prolonged periods of observation and symptomatic treatment. The relationship of these episodes to the long tissue half-life of azithromycin and subsequent prolonged exposure to antigen is unknown at present.

If an allergic reaction occurs, the drug should be discontinued and appropriate therapy should be instituted. Physicians should be aware that reappearance of the allergic symptoms may occur when symptomatic therapy is discontinued.

Clostridium difficile associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including azithromycin, and may range in severity from mild diarrhea to fatal colitis. Treatment with antibacterial agents alters the normal flora of the colon leading to overgrowth of C. difficile.

C. difficile produces toxins A and B which contribute to the development of CDAD. Hypertoxin producing strains of C. difficile cause increased morbidity and mortality, as these infections can be refractory to antimicrobial therapy and may require colectomy. CDAD must be considered in all patients who present with diarrhea following antibiotic use. Careful medical history is necessary since CDAD has been reported to occur over two months after the administration of antibacterial agents.

If CDAD is suspected or confirmed, ongoing antibiotic use not directed against C. difficile may need to be discontinued. Appropriate fluid and electrolyte management, protein supplementation, antibiotic treatment of C. difficile, and surgical evaluation should be instituted as clinically indicated.

Precautions

General:

Because azithromycin is principally eliminated via the liver, caution should be exercised when azithromycin is administered to patients with impaired hepatic function. Due to the limited data in subjects with GFR <10 mL/min, caution should be exercised when prescribing azithromycin in these patients. (See CLINICAL PHARMACOLOGY, Special Populations, Renal Insufficiency.)

Azithromycin for Injection should be reconstituted and diluted as directed and administered as an intravenous infusion over not less than 60 minutes. (See DOSAGE AND ADMINISTRATION.)

Local I.V. site reactions have been reported with the intravenous administration of azithromycin. The incidence and severity of these reactions were the same when 500 mg azithromycin were given over 1 hour (2 mg/mL as 250 mL infusion) or over 3 hours (1 mg/mL as 500 mL infusion). (See ADVERSE REACTIONS.) All volunteers who received infusate concentrations above 2 mg/mL experienced local I.V. site reactions and, therefore, higher concentrations should be avoided.

Prolonged cardiac repolarization and QT interval, imparting a risk of developing cardiac arrhythmia and torsades de pointes, have been seen in treatment with other macrolides. A similar effect with azithromycin cannot be completely ruled out in patients at increased risk for prolonged cardiac repolarization.

Exacerbation of symptoms of myasthenia gravis and new onset of myasthenic syndrome have been reported in patients receiving azithromycin therapy.

Prescribing Azithromycin for Injection in the absence of a proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria.

Information for Patients:

Patients should be directed to discontinue azithromycin and contact a physician if any signs of an allergic reaction occur.

Patients should be counseled that antibacterial drugs including Azithromycin for Injection should only be used to treat bacterial infections. They do not treat viral infections (e.g., the common cold). When Azithromycin for Injection is prescribed to treat a bacterial infection, patients should be told that although it is common to feel better early in the course of the therapy, the medication should be taken exactly as directed. Skipping doses or not completing the full course of therapy may (1) decrease the effectiveness of the immediate treatment and (2) increase the likelihood that bacteria will develop resistance and will not be treatable by Azithromycin for Injection or other antibacterial drugs in the future.

Diarrhea is a common problem caused by antibiotics which usually ends when the antibiotic is discontinued. Sometimes after starting treatment with antibiotics, patients can develop watery and bloody stools (with or without stomach cramps and fever) even as late as two or more months after having taken the last dose of the antibiotic. If this occurs, patients should contact their physician as soon as possible.

Drug Interactions:

Co-administration of nelfinavir at steady-state with a single oral dose of azithromycin resulted in increased azithromycin serum concentrations. Although a dose adjustment of azithromycin is not recommended when administered in combination with nelfinavir, close monitoring for known side effects of azithromycin, such as liver enzyme abnormalities and hearing impairment, is warranted. (See ADVERSE REACTIONS.)

Although, in a study of 22 healthy men, a 5-day course of azithromycin did not affect the prothrombin time from a subsequently administered dose of warfarin, spontaneous post-marketing reports suggest that concomitant administration of azithromycin may potentiate the effects of oral anticoagulants. Prothrombin times should be carefully monitored while patients are receiving azithromycin and oral anticoagulants concomitantly.

Drug interaction studies were performed with azithromycin and other drugs likely to be co-administered. (See CLINICAL PHARMACOLOGY, Drug-Drug Interactions.) When used in therapeutic doses, azithromycin had a modest effect on the pharmacokinetics of atorvastatin, carbamazepine, cetirizine, didanosine, efavirenz, fluconazole, indinavir, midazolam, rifabutin, sildenafil, theophylline (intravenous and oral), triazolam, trimethoprim/sulfamethoxazole or zidovudine. Co-administration with efavirenz or fluconazole had a modest effect on the pharmacokinetics of azithromycin. No dosage adjustment of either drug is recommended when azithromycin is coadministered with any of these agents.

Interactions with the drugs listed below have not been reported in clinical trials with azithromycin; however, no specific drug interaction studies have been performed to evaluate potential drug-drug interaction. Nonetheless, they have been observed with macrolide products. Until further data are developed regarding drug interactions when azithromycin and these drugs are used concomitantly, careful monitoring of patients is advised:

Digoxin – elevated digoxin concentrations.

Ergotamine or dihydroergotamine – acute ergot toxicity characterized by severe peripheral vasospasm and dysesthesia.

Terfenadine, cyclosporine, hexobarbital and phenytoin – elevated concentrations.

Laboratory Test Interactions:

There are no reported laboratory test interactions.

Carcinogenesis, Mutagenesis, Impairment of Fertility:

Long-term studies in animals have not been performed to evaluate carcinogenic potential. Azithromycin has shown no mutagenic potential in standard laboratory tests: mouse lymphoma assay, human lymphocyte clastogenic assay, and mouse bone marrow clastogenic assay. No evidence of impaired fertility due to azithromycin was found.

Pregnancy:

Teratogenic Effects. Pregnancy Category B: Reproduction studies have been performed in rats and mice at doses up to moderately maternally toxic dose concentrations (i.e., 200 mg/kg/day by the oral route). These doses, based on a mg/m2 basis, are estimated to be 4 and 2 times, respectively, the human daily dose of 500 mg by the oral route. In the animal studies, no evidence of harm to the fetus due to azithromycin was found. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, azithromycin should be used during pregnancy only if clearly needed.

Nursing Mothers:

It is not known whether azithromycin is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when azithromycin is administered to a nursing woman.

Pediatric Use:

Safety and effectiveness of azithromycin for injection in children or adolescents under 16 years have not been established. In controlled clinical studies, azithromycin has been administered to pediatric patients (age 6 months to 16 years) by the oral route. For information regarding the use of azithromycin for oral suspension in the treatment of pediatric patients, refer to the INDICATIONS AND USAGE and DOSAGE AND ADMINISTRATION sections of the prescribing information for Azithromycin for oral suspension 100 mg/5 mL and 200 mg/5 mL bottles.

Geriatric Use:

Pharmacokinetic studies with intravenous azithromycin have not been performed in older volunteers. Pharmacokinetics of azithromycin following oral administration in older volunteers (65-85 years old) were similar to those in younger volunteers (18-40 years old) for the 5-day therapeutic regimen.

In multiple-dose clinical trials of intravenous azithromycin in the treatment of community-acquired pneumonia, 45% of patients (188/414) were at least 65 years of age and 22% of patients (91/414) were at least 75 years of age. No overall differences in safety were observed between these subjects and younger subjects in terms of adverse events, laboratory abnormalities, and discontinuations. Similar decreases in clinical response were noted in azithromycin- and comparator-treated patients with increasing age.

Azithromycin for Injection contains 114 mg (4.96 mEq) of sodium per vial. At the usual recommended doses, patients would receive 114 mg (4.96 mEq) of sodium. The geriatric population may respond with a blunted natriuresis to salt loading. The total sodium content from dietary and non-dietary sources may be clinically important with regard to such diseases as congestive heart failure.

Adverse Reactions

In clinical trials of intravenous azithromycin for community-acquired pneumonia, in which 2-5 I.V. doses were given, most of the reported side effects were mild to moderate in severity and were reversible upon discontinuation of the drug. The majority of patients in these trials had one or more comorbid diseases and were receiving concomitant medications. Approximately 1.2% of the patients discontinued intravenous Azithromycin therapy, and a total of 2.4% discontinued azithromycin therapy by either the intravenous or oral route because of clinical or laboratory side effects.

In clinical trials conducted in patients with pelvic inflammatory disease, in which 1-2 I.V. doses were given, 2% of women who received monotherapy with azithromycin and 4% who received azithromycin plus metronidazole discontinued therapy due to clinical side effects.

Clinical side effects leading to discontinuations from these studies were most commonly gastrointestinal (abdominal pain, nausea, vomiting, diarrhea), and rashes; laboratory side effects leading to discontinuation were increases in transaminase levels and/or alkaline phosphatase levels.

Clinical

Overall, the most common side effects associated with treatment in adult patients who received I.V./P.O. Azithromycin for Injection in studies of community-acquired pneumonia were related to the gastrointestinal system with diarrhea/loose stools (4.3%), nausea (3.9%), abdominal pain (2.7%), and vomiting (1.4%) being the most frequently reported. Approximately 12% of patients experienced a side effect related to the intravenous infusion; most common were pain at the injection site (6.5%) and local inflammation (3.1%).

The most common side effects associated with treatment in adult women who received I.V./P.O. Azithromycin for Injection in studies of pelvic inflammatory disease were related to the gastrointestinal system. Diarrhea (8.5%) and nausea (6.6%) were most commonly reported, followed by vaginitis (2.8%), abdominal pain (1.9%), anorexia (1.9%), rash and pruritus (1.9%). When azithromycin was co-administered with metronidazole in these studies, a higher proportion of women experienced side effects of nausea (10.3%), abdominal pain (3.7%), vomiting (2.8%), application site reaction, stomatitis, dizziness, or dyspnea (all at 1.9%).

No other side effects occurred in patients on the multiple dose I.V./P.O. regimen of Azithromycin for Injection in these studies with a frequency greater than 1%.

Side effects that occurred with a frequency of 1% or less included the following:

Gastrointestinal: dyspepsia, flatulence, mucositis, oral moniliasis, and gastritis

Nervous System: headache, somnolence

Allergic: bronchospasm

Special Senses: taste perversion

Post-Marketing Experience

Adverse events reported with azithromycin during the post-marketing period in adult and/or pediatric patients for which a causal relationship may not be established include:

Allergic: Arthralgia, edema, urticaria and angioedema.

Cardiovascular: Arrhythmias including ventricular tachycardia and hypotension. There have been rare reports of QT prolongation and torsades de pointes.

Gastrointestinal: Anorexia, constipation, dyspepsia, flatulence, vomiting/diarrhea rarely resulting in dehydration, pseudomembranous colitis, pancreatitis, oral candidiasis and rare reports of tongue discoloration.

General: Asthenia, paresthesia, fatigue, malaise and anaphylaxis (rarely fatal).

Genitourinary: Interstitial nephritis and acute renal failure and vaginitis.

Hematopoietic: Thrombocytopenia.

Liver/Biliary: Abnormal liver function including hepatitis and cholestatic jaundice, as well as rare cases of hepatic necrosis and hepatic failure, some of which have resulted in death.

Nervous System: Convulsions, dizziness/vertigo, headache, somnolence, hyperactivity, nervousness, agitation and syncope.

Psychiatric: Aggressive reaction and anxiety.

Skin/Appendages: Pruritus, rarely serious skin reactions including erythema multiforme, Stevens-Johnson Syndrome and toxic epidermal necrolysis.

Special Senses: Hearing disturbances including hearing loss, deafness and/or tinnitus and rare reports of taste/smell perversion and/or loss.

Laboratory Abnormalities

Significant abnormalities (irrespective of drug relationship) occurring during the clinical trials were reported as follows:

with an incidence of 4-6%, elevated ALT (SGPT), AST (SGOT), creatinine

with an incidence of 1-3%, elevated LDH, bilirubin

with an incidence of less than 1%, leukopenia, neutropenia, decreased platelet count, and elevated serum alkaline phosphatase

When follow-up was provided, changes in laboratory tests appeared to be reversible.

In multiple-dose clinical trials involving more than 750 patients treated with Azithromycin for Injection (I.V./P.O.), less than 2% of patients discontinued azithromycin therapy because of treatment-related liver enzyme abnormalities.

Azithromycin Injection Dosage and Administration

(See INDICATIONS AND USAGE and CLINICAL PHARMACOLOGY.)

The recommended dose of Azithromycin for Injection for the treatment of adult patients with community-acquired pneumonia due to the indicated organisms is: 500 mg as a single daily dose by the intravenous route for at least two days. Intravenous therapy should be followed by azithromycin by the oral route at a single, daily dose of 500 mg, administered as two 250-mg tablets to complete a 7- to 10-day course of therapy. The timing of the switch to oral therapy should be done at the discretion of the physician and in accordance with clinical response.

The recommended dose of Azithromycin for Injection for the treatment of adult patients with pelvic inflammatory disease due to the indicated organisms is: 500 mg as a single daily dose by the intravenous route for one or two days. Intravenous therapy should be followed by azithromycin by the oral route at a single, daily dose of 250 mg to complete a 7-day course of therapy. The timing of the switch to oral therapy should be done at the discretion of the physician and in accordance with clinical response. If anaerobic microorganisms are suspected of contributing to the infection, an antimicrobial agent with anaerobic activity should be administered in combination with Azithromycin for Injection.

Renal Insufficiency

No dosage adjustment is recommended for subjects with renal impairment (GFR ≤80 mL/min). The mean AUC0-120 was similar in subjects with GFR 10-80 mL/min compared to subjects with normal renal function, whereas it increased 35% in subjects with GFR <10 mL/min compared to subjects with normal renal function. Caution should be exercised when azithromycin is administered to subjects with severe renal impairment. (See CLINICAL PHARMACOLOGY, Special Populations, Renal Insufficiency.)

Hepatic Insufficiency

THE PHARMACOKINETICS OF AZITHROMYCIN IN SUBJECTS WITH HEPATIC IMPAIRMENT HAVE NOT BEEN ESTABLISHED. NO DOSE ADJUSTMENT RECOMMENDATIONS CAN BE MADE IN PATIENTS WITH IMPAIRED HEPATIC FUNCTION (SEE CLINICAL PHARMACOLOGY, Special Populations, Hepatic Insufficiency.)

No dosage adjustment is recommended based on age or gender. (See CLINICAL PHARMACOLOGY, Special Populations.)

The infusate concentration and rate of infusion for Azithromycin for Injection should be 2 mg/mL over 1 hour. Azithromycin for Injection should not be given as a bolus or as an intramuscular injection.

Preparation of the solution for intravenous administration is as follows:

Azithromycin for Injection ADD-Vantage vials must be diluted prior to I.V. administration with the ADD-Vantage diluent container (see INSTRUCTIONS FOR USE). The ADD-Vantage vial should be joined with a 250 mL ADD-Vantage flexible diluent container (5% dextrose injection, 0.9% sodium chloride injection or 0.45% sodium chloride injection).

It is recommended that a 500-mg dose of Azithromycin for Injection, diluted as above, be infused over a period of not less than 60 minutes.

Azithromycin for Injection should not be given as a bolus or as an intramuscular injection.

Other intravenous substances, additives, or medications should not be added to Azithromycin for Injection, or infused simultaneously through the same intravenous line.

Storage

Store the lyophilized cake at 20 to 25°C (68 to 77°F). [See USP Controlled Room Temperature.]

When diluted according to the instructions (2 mg/mL), Azithromycin for Injection is stable for 24 hours at or below room temperature (30°C or 86°F), or for 7 days if stored under refrigeration (5°C or 41°F).

INSTRUCTIONS FOR USE

These instructions for use should be made available to the individuals who perform the reconstitution steps.

Parenteral drug products should be inspected visually for particulate matter prior to administration. If particulate matter is evident in reconstituted fluids, the drug solution should be discarded.

To Open:

Peel overwrap at corner and remove solution container. Some opacity of the plastic due to moisture absorption during the sterilization process may be observed. This is normal and does not affect the solution quality or safety. The opacity will diminish gradually.

To Assemble Vial and Flexible Diluent Container:

(Use Aseptic Technique)

1. Remove the protective covers from the top of the vial and the vial port on the diluent container as follows:

   a. To remove the breakaway vial cap, swing the pull ring over the top of the vial and pull down far enough to start the opening (SEE FIGURE 1.), then pull straight up to remove the cap. (SEE FIGURE 2.)

   NOTE: Once the breakaway cap has been removed, do not access vial with syringe.

   Fig. 1	Fig. 2

   b. To remove the vial port cover, grasp the tab on the pull ring, pull up to break the three tie strings, then pull back to remove the cover. (SEE FIGURE 3.)

2. Screw the vial into the vial port until it will go no further. THE VIAL MUST BE SCREWED IN TIGHTLY TO ASSURE A SEAL. This occurs approximately 1/2 turn (180°) after the first audible click. (SEE FIGURE 4.) The clicking sound does not assure a seal; the vial must be turned as far as it will go.

   NOTE: Once vial is seated, do not attempt to remove. (SEE FIGURE 4.)

3. Recheck the vial to assure that it is tight by trying to turn it further in the direction of assembly.

4. Label appropriately.

   Fig. 3	Fig. 4

   To Reconstitute the Drug: Squeeze the bottom of the diluent container gently to inflate the portion of the container surrounding the end of the drug vial. With the other hand, push the drug vial down into the container telescoping the walls of the container. Grasp the inner cap of the vial through the walls of the container. (SEE FIGURE 5.) Pull the inner cap from the drug vial. (SEE FIGURE 6.) Verify that the rubber stopper has been pulled out, allowing the drug and diluent to mix. Mix container contents thoroughly and use within the specified time. Look through the bottom of the vial to verify that the stopper has been removed and complete mixing has occurred. (SEE FIGURE 7.) If the rubber stopper is not removed from the vial and medication is not released on the first attempt, the inner cap may be manipulated back into the rubber stopper without removing the drug vial from the diluent container. Repeat steps 3 through 5. Fig. 5 Fig. 6 Fig. 7

Preparation for Administration:

(Use Aseptic Technique)

1. Confirm the activation and admixture of vial contents.

2. Check for leaks by squeezing container firmly. If leaks are found, discard unit as sterility may be impaired.

3. Close flow control clamp of administration set.

4. Remove cover from outlet port at bottom of container.

5. Insert piercing pin of administration set into port with a twisting motion until the pin is firmly seated. NOTE: See full directions on administration set carton.

6. Lift the free end of the hanger loop on the bottom of the vial, breaking the two tie strings. Bend the loop outward to lock it in the upright position, then suspend container from hanger.

7. Squeeze and release drip chamber to establish proper fluid level in chamber.

8. Open flow control clamp and clear air from set. Close clamp.

9. Attach set to venipuncture device. If device is not indwelling, prime and make venipuncture.

10. Regulate rate of administration with flow control clamp.

WARNING: Do not use flexible container in series connections.

U.S. patent 4,757,911

How is Azithromycin Injection Supplied

Azithromycin for Injection is supplied in lyophilized form in a vial equivalent to 500 mg of azithromycin for intravenous administration. Each vial also contains sodium hydroxide and 392 mg citric acid.

These are packaged as follows:

Store the lyophilized cake at 20 to 25°C (68 to 77°F). [See USP Controlled Room Temperature.]

Clinical Studies

Community-Acquired Pneumonia

In a controlled study of community-acquired pneumonia performed in the U.S., azithromycin (500 mg as a single daily dose by the intravenous route for 2-5 days, followed by 500 mg/day by the oral route to complete 7-10 days therapy) was compared to cefuroxime (2250 mg/day in three divided doses by the intravenous route for 2-5 days followed by 1000 mg/day in two divided doses by the oral route to complete 7-10 days therapy), with or without erythromycin. For the 291 patients who were evaluable for clinical efficacy, the clinical outcome rates, i.e., cure, improved, and success (cure + improved) among the 277 patients seen at 10-14 days post-therapy were as follows:

In a separate, uncontrolled clinical and microbiological trial performed in the U.S., 94 patients with community-acquired pneumonia who received azithromycin in the same regimen were evaluable for clinical efficacy. The clinical outcome rates, i.e., cure, improved, and success (cure + improved) among the 84 patients seen at 10-14 days post-therapy were as follows:

Microbiological determinations in both trials were made at the pre-treatment visit and, where applicable, were reassessed at later visits. Serological testing was done on baseline and final visit specimens. The following combined presumptive bacteriological eradication rates were obtained from the evaluable groups:

The presumed bacteriological outcomes at 10-14 days post-therapy for patients treated with azithromycin with evidence (serology and/or culture) of atypical pathogens for both trials were as follows:

Animal Toxicology

Phospholipidosis (intracellular phospholipid accumulation) has been observed in some tissues of mice, rats, and dogs given multiple doses of azithromycin. It has been demonstrated in numerous organ systems (e.g., eye, dorsal root ganglia, liver, gallbladder, kidney, spleen, and pancreas) in dogs treated with azithromycin at doses which, expressed on the basis of mg/m2, are approximately equal to the recommended adult human dose, and in rats treated at doses approximately one-sixth of the recommended adult human dose. This effect has been shown to be reversible after cessation of azithromycin treatment. Phospholipidosis has been observed to a similar extent in the tissues of neonatal rats and dogs given daily doses of azithromycin ranging from 10 days to 30 days. Based on the pharmacokinetic data, phospholipidosis has been seen in the rat (30 mg/kg dose) at observed Cmax value of 1.3 mcg/mL (six times greater than the observed Cmax of 0.216 mcg/mL at the pediatric dose of 10 mg/kg). Similarly, it has been shown in the dog (10 mg/kg dose) at observed Cmax value of 1.5 mcg/mL (seven times greater than the observed same Cmax and drug dose in the studied pediatric population). On a mg/m2 basis, 30 mg/kg dose in the neonatal rat (135 mg/m2) and 10 mg/kg dose in the neonatal dog (79 mg/m2) are approximately 0.45 and 0.3 times, respectively, the recommended dose in the pediatric patients with an average body weight of 25 kg. Phospholipidosis, similar to that seen in the adult animals, is reversible after cessation of azithromycin treatment. The significance of these findings for animals and for humans is unknown.

REFERENCES:

1. National Committee for Clinical Laboratory Standards, Methods for Dilution Antimicrobial Susceptibility Tests for Bacteria That Grow Aerobically − Fifth Edition. Approved Standard NCCLS Document M7-A5, Vol. 20, No. 2 (ISBN 1-56238-394-9). NCCLS, 940 West Valley Road, Suite 1400, Wayne, PA 19087-1898, January, 2000.

2. National Committee for Clinical Laboratory Standards, Performance Standards for Antimicrobial Disk Susceptibility Tests – Seventh Edition. Approved Standard NCCLS Document M2-A7, Vol. 20, No. 1 (ISBN 1-56238-393-0). NCCLS, 940 West Valley Road, Suite 1400, Wayne, PA 19087-1898, January, 2000.

3. National Committee for Clinical Laboratory Standards. Performance Standards for Antimicrobial Susceptibility Testing − Eleventh Informational Supplement. NCCLS Document M100-S11, Vol. 21, No. 1 (ISBN 1-56238-426-0). NCCLS, 940 West Valley Road, Suite 1400, Wayne, PA 19087-1898, January, 2001.

Revised: April, 2009

RL-2518

Revised: 12/2009Hospira, Inc.

Generic Name: Azelastine hydrochloride
Dosage Form: nasal spray, metered

Azelastine Hydrochloride Nasal Solution 0.1% (Nasal Spray), 137 mcg/spray
For Intranasal Use Only

Azelastine Description

Azelastine Hydrochloride Nasal Solution 0.1% (Nasal Spray), 137 micrograms (mcg) per spray, is an antihistamine formulated as a metered-spray solution for intranasal administration. Azelastine hydrochloride occurs as a white, almost odorless, crystalline powder with a bitter taste. It has a molecular weight of 418.37. It is sparingly soluble in water, methanol, and propylene glycol and slightly soluble in ethanol, octanol, and glycerine. It has a melting point of about 225ºC and the pH of a saturated solution is between 5.0 and 5.4. Its chemical name is (±)-1-(2H)-phthalazinone,4-[(4-chlorophenyl) methyl]-2-(hexahydro-1-methyl-1H-azepin-4-yl)-, monohydrochloride. Its molecular formula is C22H24ClN3O•HCl with the following chemical structure:

Azelastine hydrochloride nasal solution contains 0.1% Azelastine hydrochloride in an aqueous solution at pH 6.8 ± 0.3. It also contains benzalkonium chloride (125 mcg/mL), citric acid, dibasic sodium phosphate, edetate disodium, hypromellose, purified water and sodium chloride.

After priming, each metered spray delivers a 0.137 mL mean volume containing 137 mcg of Azelastine hydrochloride (equivalent to 125 mcg of Azelastine base). The bottle can deliver 200 metered sprays.

Azelastine – Clinical Pharmacology

Azelastine hydrochloride, a phthalazinone derivative, exhibits histamine H1-receptor antagonist activity in isolated tissues, animal models, and humans. Azelastine hydrochloride nasal solution is administered as a racemic mixture with no difference in pharmacologic activity noted between the enantiomers in in vitro studies. The major metabolite, desmethylAzelastine, also possesses H1-receptor antagonist activity.

Pharmacokinetics and Metabolism

After intranasal administration, the systemic bioavailability of Azelastine hydrochloride is approximately 40%. Maximum plasma concentrations (Cmax) are achieved in 2-3 hours. Based on intravenous and oral administration, the elimination half-life, steady-state volume of distribution, and plasma clearance are 22 hours, 14.5 L/kg, and 0.5 L/h/kg, respectively. Approximately 75% of an oral dose of radiolabeled Azelastine hydrochloride was excreted in the feces with less than 10% as unchanged Azelastine. Azelastine is oxidatively metabolized to the principal active metabolite, desmethylAzelastine, by the cytochrome P450 enzyme system. The specific P450 isoforms responsible for the biotransformation of Azelastine have not been identified; however, clinical interaction studies with the known CYP3A4 inhibitor erythromycin failed to demonstrate a pharmacokinetic interaction. In a multiple-dose, steady-state drug interaction study in normal volunteers, cimetidine (400 mg twice daily), a nonspecific P450 inhibitor, raised orally administered mean Azelastine (4 mg twice daily) concentrations by approximately 65%.

The major active metabolite, desmethylAzelastine, was not measurable (below assay limits) after single-dose intranasal administration of Azelastine hydrochloride. After intranasal dosing of Azelastine hydrochloride to steady-state, plasma concentrations of desmethylAzelastine range from 20-50% of Azelastine concentrations. When Azelastine hydrochloride is administered orally, desmethylAzelastine has an elimination half-life of 54 hours. Limited data indicate that the metabolite profile is similar when Azelastine hydrochloride is administered via the intranasal or oral route.

In vitro studies with human plasma indicate that the plasma protein binding of Azelastine and desmethylAzelastine are approximately 88% and 97%, respectively.

Azelastine hydrochloride administered intranasally at doses above two sprays per nostril twice daily for 29 days resulted in greater than proportional increases in Cmax and area under the curve (AUC) for Azelastine.

Studies in healthy subjects administered oral doses of Azelastine hydrochloride demonstrated linear responses in Cmax and AUC.

Special Populations

Following oral administration, pharmacokinetic parameters were not influenced by age, gender, or hepatic impairment.

Based on oral, single-dose studies, renal insufficiency (creatinine clearance <50 mL/min) resulted in a 70-75% higher Cmax and AUC compared to normal subjects. Time to maximum concentration was unchanged.

Oral Azelastine has been safely administered to over 1400 asthmatic subjects, supporting the safety of administering Azelastine hydrochloride nasal solution to allergic rhinitis patients with asthma.

Pharmacodynamics

In a placebo-controlled study (95 subjects with allergic rhinitis), there was no evidence of an effect of Azelastine hydrochloride nasal solution (2 sprays per nostril twice daily for 56 days) on cardiac repolarization as represented by the corrected QT interval (QTc) of the electrocardiogram. At higher oral exposures (≥4 mg twice daily), a nonclinically significant mean change on the QTc (3-7 millisecond increase) was observed.

Interaction studies investigating the cardiac repolarization effects of concomitantly administered oral Azelastine hydrochloride and erythromycin or ketoconazole were conducted. Oral erythromycin had no effect on Azelastine pharmacokinetics or QTc based on analysis of serial electrocardiograms. Ketoconazole interfered with the measurement of Azelastine plasma levels; however, no effects on QTc were observed (see PRECAUTIONS, Drug Interactions ).

Clinical Trials

Seasonal Allergic Rhinitis

Trials Supporting Two Sprays Per Nostril Twice Daily

U.S. placebo-controlled clinical trials of Azelastine hydrochloride nasal solution included 322 patients with seasonal allergic rhinitis who received two sprays per nostril twice a day for up to 4 weeks. These trials included 55 pediatric patients ages 12 to 16 years. Azelastine hydrochloride nasal solution showed significant improvement compared to placebo in the two primary efficacy variables – the Total Symptom Complex (TSC) and the Major Symptom Complex (MSC). The results for the MSC are shown in Table 1 as the mean change from Baseline in the average of individual symptoms of nose blows, sneezes, runny nose/sniffles, itchy nose and watery eyes as assessed by patients on a 0-5 categorical scale.

Table 1: Summary of Primary Efficacy* Analyses for Pivotal Studies Supporting Two Sprays Per Nostril Twice Daily.

Trials Supporting One Spray Per Nostril Twice Daily

Two hundred seventy five patients with seasonal allergic rhinitis received Azelastine hydrochloride nasal solution one spray per nostril twice daily for 2 weeks in two U.S. placebo-controlled trials. The primary efficacy endpoint was the change from Baseline to Day 14 in the Total Nasal Symptom Score [TNSS] (the average of individual scores of runny nose, sneezing, itchy nose, and nasal congestion) as assessed by patients on a 0-3 categorical scale. Compared to placebo, Azelastine hydrochloride nasal solution significantly improved the TNSS. The results are shown in Table 2.

Two-week studies comparing the efficacy (and safety) of Azelastine hydrochloride nasal solution two sprays per nostril twice daily versus one spray per nostril twice daily were not conducted.

Other Supporting Studies

In dose-ranging trials, administration of Azelastine hydrochloride nasal solution, two sprays per nostril twice daily, resulted in a decrease in symptoms, which reached statistical significance from saline placebo within 3 hours after initial dosing and persisted over the 12-hour dosing interval.

There were no findings on nasal examination in an 8-week study that suggested any adverse effect of Azelastine on the nasal mucosa.

Vasomotor Rhinitis

Two hundred sixteen patients with vasomotor rhinitis received Azelastine hydrochloride nasal solution two sprays per nostril twice a day in two U.S. placebo controlled trials. These patients had vasomotor rhinitis for at least one year, negative skin tests to indoor and outdoor aeroallergens, negative nasal smears for eosinophils, and negative sinus X-rays. Azelastine hydrochloride nasal solution significantly improved a symptom complex comprised of rhinorrhea, post nasal drip, nasal congestion, and sneezing.

Indications and Usage for Azelastine

Azelastine hydrochloride nasal solution is indicated for the treatment of the symptoms of seasonal allergic rhinitis such as rhinorrhea, sneezing, and nasal pruritus in adults and children 5 years and older, and for the treatment of the symptoms of vasomotor rhinitis, such as rhinorrhea, nasal congestion and postnasal drip in adults and children 12 years and older.

Contraindications

Azelastine hydrochloride nasal solution is contraindicated in patients with a known hypersensitivity to Azelastine hydrochloride or any of its components.

Precautions

Activities Requiring Mental Alertness

In clinical trials, the occurrence of somnolence has been reported in some patients taking Azelastine hydrochloride nasal solution; due caution should therefore be exercised when driving a car or operating potentially dangerous machinery while using Azelastine hydrochloride nasal spray. Concurrent use of Azelastine hydrochloride nasal solution with alcohol or other CNS depressants should be avoided because additional reductions in alertness and additional impairment of CNS performance may occur.

Information for Patients

Patients should be instructed to use Azelastine hydrochloride nasal solution only as prescribed. For the proper use of the nasal spray and to attain maximum improvement, the patient should read and follow carefully the accompanying patient instructions. Patients should be instructed to prime the delivery system before initial use and after storage for 3 or more days (see PATIENT INSTRUCTIONS FOR USE). Patients should also be instructed to store the bottle upright at room temperature with the pump tightly closed and out of the reach of children. In case of accidental ingestion by a young child, seek professional assistance or contact a poison control center immediately.

Patients should be advised against the concurrent use of Azelastine hydrochloride nasal solution with other antihistamines without consulting a physician. Patients who are, or may become, pregnant should be told that this product should be used in pregnancy or during lactation only if the potential benefit justifies the potential risks to the fetus or nursing infant. Patients should be advised to assess their individual responses to Azelastine hydrochloride nasal solution before engaging in any activity requiring mental alertness, such as driving a car or operating machinery. Patients should be advised that the concurrent use of Azelastine hydrochloride nasal solution with alcohol or other CNS depressants may lead to additional reductions in alertness and impairment of CNS performance and should be avoided (see Drug Interactions ).

Drug Interactions

Concurrent use of Azelastine hydrochloride nasal solution with alcohol or other CNS depressants should be avoided because additional reductions in alertness and additional impairment of CNS performance may occur.

Cimetidine (400 mg twice daily) increased the mean Cmax and AUC of orally administered Azelastine hydrochloride (4 mg twice daily) by approximately 65%. Ranitidine hydrochloride (150 mg twice daily) had no effect on Azelastine pharmacokinetics.

Interaction studies investigating the cardiac effects, as measured by the corrected QT interval (QTc), of concomitantly administered oral Azelastine hydrochloride and erythromycin or ketoconazole were conducted. Oral erythromycin (500 mg three times daily for seven days) had no effect on Azelastine pharmacokinetics or QTc based on analyses of serial electrocardiograms. Ketoconazole (200 mg twice daily for seven days) interfered with the measurement of Azelastine plasma concentrations; however, no effects on QTc were observed.

No significant pharmacokinetic interaction was observed with the coadministration of an oral 4 mg dose of Azelastine hydrochloride twice daily and theophylline 300 mg or 400 mg twice daily.

Carcinogenesis, Mutagenesis, Impairment of Fertility

In 2 year carcinogenicity studies in rats and mice Azelastine hydrochloride did not show evidence of carcinogenicity at oral doses up to 30 mg/kg and 25 mg/kg, respectively (approximately 240 and 100 times the maximum recommended daily intranasal dose in adults and children on a mg/m2 basis).

Azelastine hydrochloride showed no genotoxic effects in the Ames test, DNA repair test, mouse lymphoma forward mutation assay, mouse micronucleus test, or chromosomal aberration test in rat bone marrow.

Reproduction and fertility studies in rats showed no effects on male or female fertility at oral doses up to 30 mg/kg (approximately 240 times the maximum recommended daily intranasal dose in adults on a mg/m2 basis). At 68.6 mg/kg (approximately 560 times the maximum recommended daily intranasal dose in adults on a mg/m2 basis), the duration of estrous cycles was prolonged and copulatory activity and the number of pregnancies were decreased. The numbers of corpora lutea and implantations were decreased; however, pre-implantation loss was not increased.

Pregnancy Category C

Azelastine hydrochloride has been shown to cause developmental toxicity. Treatment of mice with an oral dose of 68.6 mg/kg (approximately 280 times the maximum recommended daily intranasal dose in adults on a mg/m2 basis) caused embryo-fetal death, malformations (cleft palate; short or absent tail; fused, absent or branched ribs), delayed ossification and decreased fetal weight. This dose also caused maternal toxicity as evidenced by decreased body weight. Neither fetal nor maternal effects occurred at a dose of 3 mg/kg (approximately 10 times the maximum recommended daily intranasal dose in adults on a mg/m2 basis).

In rats, an oral dose of 30 mg/kg (approximately 240 times the maximum recommended daily intranasal dose in adults on a mg/m2 basis) caused malformations (oligo-and brachydactylia), delayed ossification and skeletal variations, in the absence of maternal toxicity. At 68.6 mg/kg (approximately 560 times the maximum recommended daily intranasal dose in adults on a mg/m2 basis) Azelastine hydrochloride also caused embryo-fetal death and decreased fetal weight; however, the 68.6 mg/kg dose caused severe maternal toxicity. Neither fetal nor maternal effects occurred at a dose of 3 mg/kg (approximately 25 times the maximum recommended daily intranasal dose in adults on a mg/m2 basis).

In rabbits, oral doses of 30 mg/kg and greater (approximately 500 times the maximum recommended daily intranasal dose in adults on a mg/m2 basis) caused abortion, delayed ossification and decreased fetal weight; however, these doses also resulted in severe maternal toxicity. Neither fetal nor maternal effects occurred at a dose of 0.3 mg/kg (approximately 5 times the maximum recommended daily intranasal dose in adults on a mg/m2 basis).

There are no adequate and well-controlled clinical studies in pregnant women. Azelastine hydrochloride nasal solution should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Nursing Mothers

It is not known whether Azelastine hydrochloride is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when Azelastine hydrochloride nasal solution is administered to a nursing woman.

Pediatric Use

The safety and effectiveness of Azelastine hydrochloride nasal solution at a dose of 1 spray per nostril twice daily has been established for patients 5 through 11 years of age for the treatment of symptoms of seasonal allergic rhinitis. The safety of this dosage of Azelastine hydrochloride nasal solution was established in well-controlled studies of this dose in 176 patients 5 to 12 years of age treated for up to 6 weeks. The efficacy of Azelastine hydrochloride nasal solution at this dose is based on an extrapolation of the finding of efficacy in adults, on the likelihood that the disease course, pathophysiology and response to treatment are substantially similar in children compared to adults, and on supportive data from controlled clinical trials in patients 5 to 12 years of age at the dose of 1 spray per nostril twice daily. The safety and effectiveness of Azelastine hydrochloride nasal solution in patients below the age of 5 years have not been established.

Geriatric Use

Clinical studies of Azelastine hydrochloride nasal solution did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.

Adverse Reactions

Seasonal Allergic Rhinitis

Azelastine Hydrochloride Nasal Solution Two Sprays Per Nostril Twice Daily

Adverse experience information for Azelastine hydrochloride nasal solution is derived from six well-controlled, 2-day to 8-week clinical studies which included 391 patients who received Azelastine hydrochloride nasal solution at a dose of 2 sprays per nostril twice daily. In placebo-controlled efficacy trials, the incidence of discontinuation due to adverse reactions in patients receiving Azelastine hydrochloride nasal solution was not different from vehicle placebo (2.2% vs 2.8%, respectively). In these clinical studies, adverse events that occurred more often in patients treated with Azelastine hydrochloride nasal solution versus vehicle placebo included bitter taste (19.7% vs 0.6%), somnolence (11.5% vs 5.4%), weight increase (2.0% vs 0%), and myalgia (1.5% vs 0%).

The following table contains adverse events that were reported with frequencies ≥2% in the Azelastine hydrochloride nasal solution 2 sprays per nostril twice daily treatment group and more frequently than placebo in short-term (≤2 days) and long-term (2-8 weeks) clinical trials.

Azelastine Hydrochloride Nasal Solution One Spray Per Nostril Twice Daily

Adverse experience information for Azelastine hydrochloride nasal solution at a dose of one spray per nostril twice daily is derived from two placebo-controlled 2-week clinical studies which included 276 patients. None of the patients receiving Azelastine hydrochloride nasal solution were discontinued from these studies due to adverse reactions. Three patients receiving vehicle placebo were discontinued due to adverse reactions. Bitter taste was reported in 8.3% of patients compared to none in the placebo group. Somnolence was reported in 0.4% of patients compared to none in the placebo group.

A total of 176 patients 5 to 12 years of age were exposed to Azelastine hydrochloride nasal solution at a dose of 1 spray each nostril twice daily in 3 placebo-controlled studies. In these studies, adverse events that occurred more frequently in patients treated with Azelastine hydrochloride nasal solution than with placebo, and that were not represented in the adult adverse event table above include rhinitis/cold symptoms (17.0% vs 9.5%), cough (11.4% vs 8.3%), conjunctivitis (5.1% vs 1.8%), and asthma (4.5% vs 4.1%).

The following events were observed infrequently (<2% and exceeding placebo incidence) in patients who received Azelastine hydrochloride nasal solution dosed at 1 or 2 sprays per nostril twice daily in U.S. clinical trials.

Cardiovascular: flushing, hypertension, tachycardia.

Dermatological: contact dermatitis, eczema, hair and follicle infection, furunculosis, skin laceration.

Digestive: constipation, gastroenteritis, glossitis, ulcerative stomatitis, vomiting, increased SGPT, aphthous stomatitis, diarrhea, toothache.

Metabolic and Nutritional: increased appetite.

Musculoskeletal: myalgia, temporomandibular dislocation, rheumatoid arthritis.

Neurological: hyperkinesia, hypoesthesia, vertigo.

Psychological: anxiety, depersonalization, depression, nervousness, sleep disorder, thinking abnormal.

Respiratory: bronchospasm, coughing, throat burning, laryngitis, bronchitis, dry throat, nocturnal dyspnea, nasopharyngitis, nasal congestion, pharyngolaryngeal pain, sinusitis, nasal dryness, paranasal sinus hypersecretion, post nasal drip.

Special Senses: conjunctivitis, eye abnormality, eye pain, watery eyes, taste loss.

Urogenital: albuminuria, amenorrhea, breast pain, hematuria, increased urinary frequency.

Whole Body: allergic reaction, back pain, herpes simplex, viral infection, malaise, pain in extremities, abdominal pain, pyrexia.

Adverse Reactions

Vasomotor Rhinitis

Adverse experience information for Azelastine hydrochloride nasal solution is derived from two placebo-controlled clinical studies which included 216 patients who received Azelastine hydrochloride nasal solution at a dose of 2 sprays per nostril twice daily for up to 28 days. The incidence of discontinuation due to adverse reactions in patients receiving Azelastine hydrochloride nasal solution was not different from vehicle placebo (2.8% vs 2.9%, respectively).

The following adverse events were reported with frequencies ≥2% in the Azelastine hydrochloride nasal solution treatment group and more frequently than placebo.

Events observed infrequently (<2% and exceeding placebo incidence) in patients who received Azelastine hydrochloride nasal solution (2 sprays/nostril twice daily) in U.S. clinical trials in vasomotor rhinitis were similar to those observed in U.S. clinical trials in seasonal allergic rhinitis.

In controlled trials involving nasal and oral Azelastine hydrochloride formulations, there were infrequent occurrences of hepatic transaminase elevations. The clinical relevance of these reports has not been established.

In addition, the following spontaneous adverse events have been reported during the marketing of Azelastine hydrochloride nasal solution and causal relationship with the drug is unknown: anaphylactoid reaction, application site irritation, atrial fibrillation, chest pain, confusion, dyspnea, facial edema, involuntary muscle contractions, palpitations, paresthesia, parosmia, pruritus, rash, disturbance or loss of sense of smell and/or taste, tolerance, urinary retention, vision abnormal, and xerophthalmia.

Overdosage

There have been no reported overdosages with Azelastine hydrochloride nasal solution. Acute overdosage by adults with this dosage form is unlikely to result in clinically significant adverse events, other than increased somnolence, since one bottle of Azelastine hydrochloride nasal solution contains 30 mg of Azelastine hydrochloride. Clinical studies in adults with single doses of the oral formulation of Azelastine hydrochloride (up to 16 mg) have not resulted in increased incidence of serious adverse events. General supportive measures should be employed if overdosage occurs. There is no known antidote to Azelastine hydrochloride nasal solution. Oral ingestion of antihistamines has the potential to cause serious adverse effects in young children. Accordingly, Azelastine hydrochloride nasal solution should be kept out of the reach of children. Oral doses of 120 mg/kg and greater (approximately 460 times the maximum recommended daily intranasal dose in adults and children on a mg/m2 basis) were lethal in mice. Responses seen prior to death were tremor, convulsions, decreased muscle tone, and salivation. In dogs, single oral doses as high as 10 mg/kg (approximately 260 times the maximum recommended daily intranasal dose in adults and children on a mg/m2 basis) were well tolerated, but single oral doses of 20 mg/kg were lethal.

Azelastine Dosage and Administration

Seasonal Allergic Rhinitis

The recommended dose of Azelastine hydrochloride nasal solution in adults and children 12 years and older with seasonal allergic rhinitis is one or two sprays per nostril twice daily. The recommended dose of Azelastine hydrochloride nasal solution in children 5 years to 11 years of age is one spray per nostril twice daily.

Vasomotor Rhinitis

The recommended dose of Azelastine hydrochloride nasal solution in adults and children 12 years and older with vasomotor rhinitis is two sprays per nostril twice daily. Before initial use, the delivery system should be primed with 4 sprays or until a fine mist appears. When 3 or more days have elapsed since the last use, the pump should be reprimed with 2 sprays or until a fine mist appears.

CAUTION: Avoid spraying in the eyes.

Directions for Use: Illustrated patient instructions for proper use accompany each package of Azelastine hydrochloride nasal solution.

How is Azelastine Supplied

Azelastine Hydrochloride Nasal Solution 0.1% (Nasal Spray), 137 mcg/spray, (NDC 60505-0833-5) is supplied as a package containing 200 metered sprays in a high-density polyethylene (HDPE) bottle fitted with a metered-dose spray pump unit. A leaflet of patient instructions is also provided. The spray pump unit consists of a nasal spray pump fitted with a white safety clip and a white plastic dust cover.

The Azelastine Hydrochloride Nasal Solution 0.1% (Nasal Spray), 137 mcg/spray, bottle contains 30 mg (1 mg/mL) of Azelastine hydrochloride. The bottle can deliver 200 metered sprays. Each spray delivers a mean of 0.137 mL solution containing 137 mcg of Azelastine hydrochloride.

Storage

Store upright at 20º-25ºC (68º-77ºF) [See USP Controlled Room Temperature]. Protect from freezing.

Keep bottle tightly closed and away from children.

241533

January 2009

PATIENT: How to Use Instructions

FOR INTRANASAL USE ONLY 

IMPORTANT:  FOLLOW INSTRUCTIONS CAREFULLY TO ENSURE PROPER DOSING.

DOSING:  The dosage of Azelastine hydrochloride nasal solution is 1 spray per nostril twice daily for pediatric patients (ages 5-11 years) with seasonal allergic rhinitis. For patients age 12 and older with seasonal allergic rhinitis the dosage is one or two sprays per nostril twice daily.  For patients age 12 and older with nonallergic vasomotor rhinitis the dosage is two sprays per nostril twice daily. Keep your head tilted downward when spraying. Alternate sprays between nostrils. Breathe gently to avoid drawing any medication into the throat. Follow the instructions below to use your Azelastine Hydrochloride Nasal Solution 0.1% (Nasal Spray) pump.

TO PRIME:

1. Remove and retain the white spray tip dust cover and white spray clip.

2. Prime for initial use by putting two fingers on the shoulders of the spray pump unit and place your thumb on the bottom of the bottle. Press upward with thumb, release, and repeat until a fine mist appears (4 sprays or less). Now your pump is primed and ready to use.

3. If the solution is delivered in a stream of liquid, it may fail to provide maximum benefit and cause some discomfort. A fine mist can be produced only by a rapid and firm pumping action.

4. When 3 or more days have elapsed since the last use, the pump should be reprimed with 2 sprays or until a fine mist appears.

TO USE:

1. Gently blow nose to clear nostrils.

2. Keep your head tilted downward toward your toes.

3. Place the spray tip ¼ to ½ inch into one nostril. Hold bottle vertically upright (as shown), allowing spray tip to aim toward the back of the nose. Close other nostril with finger, rapidly press once with thumb and sniff gently at the same time. You may feel a brief burning or stinging sensation after using the unit.

4. Repeat in other nostril.

5. For patients aged 12 and over who were instructed by their doctor to administer 2 sprays in each nostril, repeat Steps 2 and 3 for second spray, again alternating sprays between nostrils.

6. Breathe in gently, and do not tilt head back after dosing to avoid drawing medication into the throat (where it will be tasted).

CAUTION:  Keep bottle tightly closed and away from children. In case of accidental ingestion by a young child, seek professional assistance or contact a poison control center immediately. Do not spray in eyes.

NOTE:  Keep the dust cover and safety clip on the spray pump unit when not in use. After each use and before replacing the dust cover, wipe the spray tip with a clean tissue or cloth.

TO CLEAN:

1. If spray nozzle becomes clogged, DO NOT ATTEMPT TO CLEAR IT USING A POINTED OBJECT.Remove the spray pump unit from the bottle.

2. Soak only the spray pump unit in warm water.Squirt several times while holding under water.

3. Make sure the spray pump unit is dry.

4. Reinsert the pump into the open bottle and tighten by turning clockwise.

5. To avoid leakage, firm pressure is required to ensure that the pump is fully threaded onto the bottle.

6. Follow instructions for priming.

Store upright at 20º-25ºC (68º-77ºF) [See USP Controlled Room Temperature]. Protect from freezing.  Keep bottle tightly closed and away from children.

241533

January 2009

PRINCIPAL DISPLAY PANEL

Representative sample of labeling (see the HOW SUPPLIED section for complete listing):

PRINCIPAL DISPLAY PANEL – 137 mcg/spray BOTTLE LABEL

APOTEX CORP. NDC 60505-0833-5

Azelastine HYDROCHLORIDE NASAL SOLUTION 0.1% (NASAL SOLUTION),

137 mcg/spray

Rx only

30 mL

Revised: 02/2010Apotex Corp.