1 INDICATIONS AND USAGE Azithromycin tablets are a macrolide antibacterial drug indicated for the treatment of patients with mild to moderate infections caused by susceptible strains of the designated microorganisms in the specific conditions listed below.

Azithromycin tablets are a macrolide antibacterial drug indicated for mild to moderate infections caused by designated, susceptible bacteria: • Mycobacterial Infections (1.2) To reduce the development of drug-resistant bacteria and maintain the effectiveness of azithromycin tablets and other antibacterial drugs, azithromycin tablets should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria.

(1.3) 1.2 Mycobacterial Infections Prophylaxis of Disseminated Mycobacterium avium complex (MAC) Disease Azithromycin tablets taken alone or in combination with rifabutin at its approved dose, are indicated for the prevention of disseminated MAC disease in persons with advanced HIV infection [see Dosage and Administration (2)] .

Treatment of Disseminated MAC Disease Azithromycin tablets taken in combination with ethambutol, are indicated for the treatment of disseminated MAC infections in persons with advanced HIV infection [see Use in Specific Populations (8.4) and Clinical Studies (14.1)].

1.3 Usage To reduce the development of drug-resistant bacteria and maintain the effectiveness of azithromycin tablets and other antibacterial drugs, azithromycin tablets should be used only to treat 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.

6 ADVERSE REACTIONS The following clinically significant adverse reactions are described elsewhere in labeling: Hypersensitivity [see Warnings and Precautions (5.1)] Hepatotoxicity [see Warnings and Precautions (5.2)] Infantile Hypertrophic Pyloric Stenosis (IHPS) [see Warnings and Precautions (5.3)] QT Prolongation [see Warnings and Precautions (5.4)] Cardiovascular Death [see Warnings and Precautions (5.5)] Clostridiodes difficile- Associated Diarrhea (CDAD) [see Warnings and Precautions (5.6)] Exacerbation of Myasthenia Gravis [see Warnings and Precautions (5.7)] The most common adverse reactions are diarrhea (5%), nausea (3%), abdominal pain (3%), or vomiting (no percent given).

(6) To report SUSPECTED ADVERSE REACTIONS, contact Alembic Pharmaceuticals limited at 1-866-210-9797 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

In clinical trials, most of the reported adverse reactions were mild to moderate in severity and were reversible upon discontinuation of the drug.

Approximately 0.7% of the patients from the multiple-dose clinical trials discontinued azithromycin therapy because of treatment-related adverse reactions.

Serious adverse reactions included angioedema and cholestatic jaundice.

Most of the adverse reactions leading to discontinuation were related to the gastrointestinal tract, e.g., nausea, vomiting, diarrhea, or abdominal pain [see Clinical Studies (14.2)].

Multiple-dose regimen Overall, the most common adverse reactions in adult patients receiving a multiple-dose regimen of azithromycin were related to the gastrointestinal system with diarrhea/loose stools (5%), nausea (3%), and abdominal pain (3%) being the most frequently reported.

No other adverse reactions occurred in patients on the multiple-dose regimen of azithromycin with a frequency greater than 1%.

Adverse reactions that occurred with a frequency of 1% or less included the following: Cardiovascular: Palpitations and chest pain.

Gastrointestinal: Dyspepsia, flatulence, vomiting, melena, and cholestatic jaundice.

Genitourinary: Monilia, vaginitis, and nephritis.

Nervous System: Dizziness, headache, vertigo, and somnolence.

General: Fatigue.

Allergic: Rash, photosensitivity, and angioedema.

Chronic therapy with 1200 mg weekly regimen The nature of adverse reactions seen with the 1200 mg weekly dosing regimen for the prevention of Mycobacterium avium infection in severely immunocompromised HIV-infected patients were similar to those seen with short-term dosing regimens [see Clinical Studies (14)].

Chronic therapy with 600 mg daily regimen combined with ethambutol The nature of adverse reactions seen with the 600 mg daily dosing regimen for the treatment of Mycobacterium avium complex infection in severely immunocompromised HIV-infected patients were similar to those seen with short term dosing regimens.

Five percent of patients experienced reversible hearing impairment in the pivotal clinical trial for the treatment of disseminated MAC in patients with AIDS.

Hearing impairment has been reported with macrolide antibiotics, especially at higher doses.

Other treatment-related adverse reactions occurring in >5% of subjects and seen at any time during a median of 87.5 days of therapy include: abdominal pain (14%), nausea (14%), vomiting (13%), diarrhea (12%), flatulence (5%), headache (5%), and abnormal vision (5%).

Discontinuations from treatment due to laboratory abnormalities or adverse reactions considered related to study drug occurred in 8 of 88 (9.1%) of subjects.

6.2 Postmarketing Experience The following adverse reactions have been identified during post approval use of azithromycin.

Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

Adverse reactions reported with azithromycin during the postmarketing 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 reports of QT prolongation, torsades de pointes , and cardiovascular death.

Gastrointestinal: Anorexia, constipation, dyspepsia, flatulence, vomiting/diarrhea pseudomembranous colitis, pancreatitis, oral candidiasis, pyloric stenosis, and tongue discoloration.

General: Asthenia, paresthesia, fatigue, malaise, and anaphylaxis.

Genitourinary: Interstitial nephritis, acute renal failure, and vaginitis.

Hematopoietic: Thrombocytopenia.

Liver/Biliary: Abnormal liver function, hepatitis, cholestatic jaundice, hepatic necrosis, and hepatic failure [see Warnings and Precautions (5.2)] .

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

Psychiatric: Aggressive reaction and anxiety.

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

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

6.3 Laboratory Abnormalities Significant abnormalities (irrespective of drug relationship) occurring during the clinical trials were reported as follows: · With an incidence of 1 to 2%, elevated serum creatine phosphokinase, potassium, ALT (SGPT), GGT, and AST (SGOT).

· With an incidence of less than 1%, leukopenia, neutropenia, decreased platelet count, elevated serum alkaline phosphatase, bilirubin, BUN, creatinine, blood glucose, LDH, and phosphate.

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

In multiple-dose clinical trials involving more than 3000 patients, 3 patients discontinued therapy because of treatment-related liver enzyme abnormalities and 1 because of a renal function abnormality.

In a phase 1 drug interaction study performed in normal volunteers, 1 of 6 subjects given the combination of azithromycin and rifabutin, 1 of 7 given rifabutin alone, and 0 of 6 given azithromycin alone developed a clinically significant neutropenia (<500 cells/mm 3 ).

Laboratory abnormalities seen in clinical trials for the prevention of disseminated Mycobacterium avium disease in severely immunocompromised HIV-infected patients [see Clinical Studies (14)] Chronic therapy (median duration: 87.5 days, range: 1 to 229 days) that resulted in laboratory abnormalities in >5% of subjects with normal baseline values in the pivotal trial for treatment of disseminated MAC in severely immunocompromised HIV - infected patients treated with azithromycin 600 mg daily in combination with ethambutol include: a reduction in absolute neutrophils to <50% of the lower limit of normal (10/52, 19%) and an increase to five times the upper limit of normal in alkaline phosphatase (3/35, 9%).

These findings in subjects with normal baseline values are similar when compared to all subjects for analyses of neutrophil reductions (22/75, 29%) and elevated alkaline phosphatase (16/80, 20%).

Causality of these laboratory abnormalities due to the use of study drug has not been established.