Zithromax

1 INDICATIONS AND USAGE ZITHROMAX is a macrolide antibacterial drug indicated for treatment of patients with mild to moderate infections caused by susceptible strains of the designated microorganisms in the specific conditions listed below: • Acute bacterial exacerbations of chronic bronchitis in adults ( 1.1 ) • Acute bacterial sinusitis in adults ( 1.1 ) • Uncomplicated skin and skin structure infections in adults ( 1.1 ) • Urethritis and cervicitis in adults ( 1.1 ) • Genital ulcer disease in men ( 1.1 ) • Acute otitis media in pediatric patients (6 months of age and older) ( 1.2 ) • Community-acquired pneumonia in adults and pediatric patients (6 months of age and older) ( 1.1 , 1.2 ) • Pharyngitis/tonsillitis in adults and pediatric patients (2 years of age and older) ( 1.1 , 1.2 ) Limitation of Use: ZITHROMAX is not recommended in patients with pneumonia who are judged to be inappropriate for oral therapy because of moderate to severe illness or risk factors. ( 1.3 ) To reduce the development of drug-resistant bacteria and maintain the effectiveness of ZITHROMAX and other antibacterial drugs, ZITHROMAX should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. ( 1.4 ) 1.1 Indications in Adult Patients ZITHROMAX is indicated in adult patients for the treatment of mild to moderate infections caused by susceptible strains of the designated microorganisms in the specific conditions listed below: • Acute bacterial exacerbations of chronic bronchitis due to Haemophilus influenzae , Moraxella catarrhalis , or Streptococcus pneumoniae . • Acute bacterial sinusitis due to Haemophilus influenzae , Moraxella catarrhalis . or Streptococcus pneumoniae . • Community‐acquired pneumonia due to Chlamydophila pneumoniae , Haemophilus influenzae , Mycoplasma pneumoniae , or Streptococcus pneumoniae in patients appropriate for oral therapy. • Pharyngitis/tonsillitis caused by Streptococcus pyogenes as an alternative to first‐line therapy in individuals who cannot use first‐line therapy. • Uncomplicated skin and skin structure infections due to Staphylococcus aureus , Streptococcus pyogenes , or Streptococcus agalactiae . • Urethritis and cervicitis due to Chlamydia trachomatis or Neisseria gonorrhoeae . • Genital ulcer disease in men due to Haemophilus ducreyi (chancroid). Due to the small number of women included in clinical trials, the efficacy of azithromycin in the treatment of chancroid in women has not been established. 1.2 Indications in Pediatric Patients ZITHROMAX is indicated in pediatric patients for the treatment of mild to moderate infections caused by susceptible strains of the designated microorganisms in the specific conditions listed below: [see Use in Specific Populations (8.4) and Clinical Studies (14.2) ] . • Acute otitis media caused by Haemophilus influenzae , Moraxella catarrhalis , or Streptococcus pneumoniae , in pediatric patients 6 months of age and older. • Community‐acquired pneumonia due to Chlamydophila pneumoniae , Haemophilus influenzae , Mycoplasma pneumoniae , or Streptococcus pneumoniae in pediatric patients 6 months of age and older appropriate for oral therapy. • Pharyngitis/tonsillitis caused by Streptococcus pyogenes as an alternative to first-line therapy in individuals who cannot use first-line therapy in pediatric patients 2 years of age and older. 1.3 Limitations of Use Azithromycin is not recommended in patients with pneumonia who are judged to be inappropriate for oral therapy because of moderate to severe illness or risk factors such as any of the following: • patients with cystic fibrosis, • patients with nosocomial infections, • patients with known or suspected bacteremia, • patients requiring hospitalization, • elderly or debilitated patients, or • patients with significant underlying health problems that may compromise their ability to respond to their illness (including immunodeficiency or functional asplenia). 1.4 Usage T …

2 DOSAGE AND ADMINISTRATION Recommended Dosage for Adult Patients ( 2.1 ) Infection Recommended Dose/Duration of Therapy Community-acquired pneumonia (mild severity) Pharyngitis/tonsillitis (second-line therapy) Skin/skin structure (uncomplicated) 500 mg as a single dose on Day 1, followed by 250 mg once daily on Days 2 through 5. Acute bacterial exacerbations of chronic bronchitis (mild to moderate) 500 mg as a single dose on Day 1, followed by 250 mg once daily on Days 2 through 5 or 500 mg once daily for 3 days. Acute bacterial sinusitis 500 mg once daily for 3 days. Genital ulcer disease (chancroid) Non-gonococcal urethritis and cervicitis One single 1 gram dose. Gonococcal urethritis and cervicitis One single 2 gram dose. Recommended Dosage for Pediatric Patients ( 2.2 ) Infection Recommended Dose/Duration of Therapy Acute otitis media (6 months of age and older) 30 mg/kg as a single dose or 10 mg/kg once daily for 3 days or 10 mg/kg as a single dose on Day 1 followed by 5 mg/kg/day on Days 2 through 5. Acute bacterial sinusitis (6 months of age and older) 10 mg/kg once daily for 3 days. Community-acquired pneumonia (6 months of age and older) 10 mg/kg as a single dose on Day 1 followed by 5 mg/kg once daily on Days 2 through 5. Pharyngitis/tonsillitis (2 years of age and older) 12 mg/kg once daily for 5 days. 2.1 Recommended Dosage for Adult Patients Recommended dosages and durations of therapy in adult patient populations vary by indications [see Indications and Usage (1.1) and Clinical Pharmacology (12.3) ]. ZITHROMAX tablets and ZITHROMAX for oral suspension can be taken with or without food. Table 1. Recommended dosage for Adult Patients by Indication Infection Due to the indicated microorganisms [see Indications and Usage (1.1) ]. Recommended Dose/Duration of Therapy Community-acquired pneumonia Pharyngitis/tonsillitis (second-line therapy) Skin/skin structure (uncomplicated) 500 mg as a single dose on Day 1, followed by 250 mg once daily on Days 2 through 5 Acute bacterial exacerbations of chronic obstructive pulmonary disease 500 mg once daily for 3 days OR 500 mg as a single dose on Day 1, followed by 250 mg once daily on Days 2 through 5 Acute bacterial sinusitis 500 mg once daily for 3 days Genital ulcer disease (chancroid) One single 1 gram dose Non-gonococcal urethritis and cervicitis One single 1 gram dose Gonococcal urethritis and cervicitis One single 2 gram dose 2.2 Recommended Dosage for Pediatric Patients Recommended dosages and durations of therapy in pediatric patient populations vary by indications [see Indications and Usage (1.2) and Clinical Pharmacology (12.3) ] . ZITHROMAX for oral suspension can be taken with or without food. Table 2. Recommended dose for Pediatric Patients by Indication Infection Due to the indicated microorganisms [see Indications and Usage (1.2) and Use in Specific Populations (8.4) ]. Recommended Dose/Duration of Therapy see dosing tables below for maximum doses evaluated by indication. Acute otitis media 30 mg/kg as a single dose or 10 mg/kg once daily for 3 days or 10 mg/kg as a single dose on Day 1 followed by 5 mg/kg/day on Days 2 through 5. Acute bacterial sinusitis 10 mg/kg once daily for 3 days. Community-acquired pneumonia 10 mg/kg as a single dose on Day 1 followed by 5 mg/kg once daily on Days 2 through 5. Pharyngitis/tonsillitis 12 mg/kg once daily for 5 days. PEDIATRIC DOSAGE GUIDELINES FOR OTITIS MEDIA, ACUTE BACTERIAL SINUSITIS, AND COMMUNITY-ACQUIRED PNEUMONIA (Age 6 months and above, [see Use in Specific Populations (8.4) ] ) Based on Body Weight Table 3. Otitis Media and Community-Acquired Pneumonia: (5-Day Regimen) Effectiveness of the 3-day or 1-day regimen in pediatric patients with community-acquired pneumonia has not been established [see Use in Specific Populations (8.4) ] . Dosing Calculated on 10 mg/kg/day Day 1 and 5 mg/kg/day Days 2 to 5. Weight 100 mg/5 mL 200 mg/5 mL Total mL per Treatment Course Total mg per Treatment Course Kg Day 1 Days 2-5 Da …

3 DOSAGE FORMS AND STRENGTHS ZITHROMAX 250 mg tablets are supplied as pink modified capsular shaped, engraved, film-coated tablets containing azithromycin dihydrate equivalent to 250 mg of azithromycin. ZITHROMAX 250 mg tablets are engraved with "PFIZER" on one side and "306" on the other, or "Pfizer" on one side and "ZTM 250" on the other. ZITHROMAX 500 mg tablets are supplied as pink modified capsular shaped, engraved, film-coated tablets containing azithromycin dihydrate equivalent to 500 mg of azithromycin. ZITHROMAX 500 mg tablets are engraved with "Pfizer" on one side and "ZTM500" on the other. ZITHROMAX for oral suspension after constitution contains a flavored suspension. ZITHROMAX for oral suspension is supplied to provide 100 mg/5 mL or 200 mg/5 mL suspension in bottles. • ZITHROMAX tablets 250 mg and 500 mg ( 3 ) • ZITHROMAX for oral suspension 100 mg/5 mL and 200 mg/5 mL ( 3 )

4 CONTRAINDICATIONS • Patients with known hypersensitivity to azithromycin, erythromycin, any macrolide or ketolide drug. ( 4.1 ) • Patients with a history of cholestatic jaundice/hepatic dysfunction associated with prior use of azithromycin. ( 4.2 ) 4.1 Hypersensitivity ZITHROMAX is contraindicated in patients with known hypersensitivity to azithromycin, erythromycin, any macrolide or ketolide drug. 4.2 Hepatic Dysfunction ZITHROMAX is contraindicated in patients with a history of cholestatic jaundice/hepatic dysfunction associated with prior use of azithromycin.

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) ] • Clostridioides difficile- Associated Diarrhea (CDAD) [see Warnings and Precautions (5.6) ] • Exacerbation of Myasthenia Gravis [see Warnings and Precautions (5.7) ] Most common adverse reactions are diarrhea (5 to 14%), nausea (3 to 18%), abdominal pain (3 to 7%), or vomiting (2 to 7%). ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Pfizer Inc. at 1-800-438-1985 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 side effects were mild to moderate in severity and were reversible upon discontinuation of the drug. Potentially serious adverse reactions of angioedema and cholestatic jaundice were reported. Approximately 0.7% of the patients (adults and pediatric patients) from the 5-day multiple-dose clinical trials discontinued ZITHROMAX therapy because of treatment-related adverse reactions. In adults given 500 mg/day for 3 days, the discontinuation rate due to treatment-related adverse reactions was 0.6%. In clinical trials in pediatric patients given 30 mg/kg, either as a single dose or over 3 days, discontinuation from the trials due to treatment-related adverse reactions was approximately 1%. 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) ] Clinical Trials Experience in Adults Multiple-dose regimens: Overall, the most common treatment-related adverse reactions in adult patients receiving multiple-dose regimens of ZITHROMAX were related to the gastrointestinal system with diarrhea/loose stools (4 to 5%), nausea (3%), and abdominal pain (2 to 3%) being the most frequently reported. No other adverse reactions occurred in patients on the multiple-dose regimens of ZITHROMAX with a frequency greater than 1%. Adverse reactions that occurred with a frequency of 1% or less included the following: Cardiovascular: Palpitations, 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, pruritus, photosensitivity, and angioedema. Single 1-gram dose regimen: Overall, the most common adverse reactions in patients receiving a single-dose regimen of 1 gram of ZITHROMAX were related to the gastrointestinal system and were more frequently reported than in patients receiving the multiple-dose regimen. Adverse reactions that occurred in patients on the single 1-gram dosing regimen of ZITHROMAX with a frequency of 1% or greater included diarrhea/loose stools (7%), nausea (5%), abdominal pain (5%), vomiting (2%), dyspepsia (1%), and vaginitis (1%). Single 2-gram dose regimen: Overall, the most common adverse reactions in patients receiving a single 2-gram dose of ZITHROMAX were related to the gastrointestinal system. Adverse reactions that occurred in patients in this study with a frequency of 1% or greater included nausea (18%), diarrhea/loose stools (14%), vomiting (7%), abdominal pain (7%), vaginitis (2%), dyspepsia (1%), and dizziness (1%). The majority of these complaints were mild in nature. Clinical Trials Experience in Pediatric Patients Single and Multiple-dose regi …

7 DRUG INTERACTIONS • Nelfinavir: Close monitoring for known adverse reactions of azithromycin, such as liver enzyme abnormalities and hearing impairment, is warranted. ( 7.1 ) • Warfarin: Use with azithromycin may increase coagulation times; monitor prothrombin time. ( 7.2 ) 7.1 Nelfinavir 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 adverse reactions of azithromycin, such as liver enzyme abnormalities and hearing impairment, is warranted. [see Adverse Reactions (6) ] 7.2 Warfarin Spontaneous postmarketing reports suggest that concomitant administration of azithromycin may potentiate the effects of oral anticoagulants such as warfarin, although the prothrombin time was not affected in the dedicated drug interaction study with azithromycin and warfarin. Prothrombin times should be carefully monitored while patients are receiving azithromycin and oral anticoagulants concomitantly. 7.3 Potential Drug-Drug Interaction with Macrolides Interactions with digoxin, colchicine or phenytoin have not been reported in clinical trials with azithromycin. No specific drug interaction studies have been performed to evaluate potential drug-drug interaction. However, drug interactions have been observed with other macrolide products. Until further data are developed regarding drug interactions when digoxin, colchicine or phenytoin are used with azithromycin careful monitoring of patients is advised.

8 USE IN SPECIFIC POPULATIONS Geriatric use: Elderly patients may be more susceptible to development of torsades de pointes arrhythmias. ( 8.5 ) 8.1 Pregnancy Risk Summary Available data from published literature and postmarketing experience over several decades with azithromycin use in pregnant women have not identified any drug-associated risks for major birth defects, miscarriage, or adverse maternal or fetal outcomes (see Data ) . Developmental toxicity studies with azithromycin in rats, mice, and rabbits showed no drug-induced fetal malformations at doses up to 4, 2, and 2 times, respectively, an adult human daily dose of 500 mg based on body surface area. Decreased viability and delayed development were observed in the offspring of pregnant rats administered azithromycin from day 6 of pregnancy through weaning at a dose equivalent to 4 times an adult human daily dose of 500 mg based on body surface area (see Data ) . The estimated background risk of major birth defects and miscarriage for the indicated populations is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. Data Human Data Available data from published observational studies, case series, and case reports over several decades do not suggest an increased risk for major birth defects, miscarriage, or adverse maternal or fetal outcomes with azithromycin use in pregnant women. Limitations of these data include the lack of randomization and inability to control for confounders such as underlying maternal disease and maternal use of concomitant medications. Animal Data Azithromycin administered during the period of organogenesis did not cause fetal malformations in rats and mice at oral doses up to 200 mg/kg/day (moderately maternally toxic). Based on body surface area, this dose is approximately 4 (rats) and 2 (mice) times an adult human daily dose of 500 mg. In rabbits administered azithromycin at oral doses of 10, 20, and 40 mg/kg/day during organogenesis, reduced maternal body weight and food consumption were observed in all groups; no evidence of fetotoxicity or teratogenicity was observed at these doses, the highest of which is estimated to be 2 times an adult human daily dose of 500 mg based on body surface area. In a pre- and postnatal development study, azithromycin was administered orally to pregnant rats from day 6 of pregnancy until weaning at doses of 50 or 200 mg/kg/day. Maternal toxicity (reduced food consumption and body weight gain; increased stress at parturition) was observed at the higher dose. Effects in the offspring were noted at 200 mg/kg/day during the postnatal development period (decreased viability, delayed developmental landmarks). These effects were not observed in a pre- and postnatal rat study when up to 200 mg/kg/day of azithromycin was given orally beginning on day 15 of pregnancy until weaning. 8.2 Lactation Risk Summary Azithromycin is present in human milk (see Data ) . Non-serious adverse reactions have been reported in breastfed infants after maternal administration of azithromycin (see Clinical Considerations ) . There are no available data on the effects of azithromycin on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for ZITHROMAX and any potential adverse effects on the breastfed infant from ZITHROMAX or from the underlying maternal condition. Clinical Considerations Advise women to monitor the breastfed infant for diarrhea, vomiting, or rash. Data Azithromycin breastmilk concentrations were measured in 20 women after receiving a single 2 g oral dose of azithromycin during labor. Breastmilk samples collected on days 3 and 6 postpartum as well as 2 and 4 weeks postpartum revealed the presence of azithromycin in breastmilk …

12.1 Mechanism of Action Azithromycin is a macrolide antibacterial drug. [see Microbiology (12.4) ]

Mechanism of Action Azithromycin acts by binding to the 23S rRNA of the 50S ribosomal subunit of susceptible microorganisms inhibiting bacterial protein synthesis and impeding the assembly of the 50S ribosomal subunit. Resistance Azithromycin demonstrates cross resistance with erythromycin. The most frequently encountered mechanism of resistance to azithromycin is modification of the 23S rRNA target, most often by methylation. Ribosomal modifications can determine cross resistance to other macrolides, lincosamides, and streptogramin B (MLS B phenotype). Antimicrobial Activity Azithromycin has been shown to be active against most isolates of the following microorganisms, both in vitro and in clinical infections. [see Indications and Usage (1) ] Gram-Positive Bacteria Staphylococcus aureus Streptococcus agalactiae Streptococcus pneumoniae Streptococcus pyogenes Gram-Negative Bacteria Haemophilus ducreyi Haemophilus influenzae Moraxella catarrhalis Neisseria gonorrhoeae Other Bacteria Chlamydophila pneumoniae Chlamydia trachomatis Mycoplasma pneumoniae The following in vitro data are available, but their clinical significance is unknown. At least 90 percent of the following bacteria exhibit an in vitro minimum inhibitory concentration (MIC) less than or equal to the susceptible breakpoint for azithromycin against isolates of similar genus or organism group. However, the efficacy of azithromycin in treating clinical infections caused by these bacteria has not been established in adequate and well-controlled clinical trials. Gram-Positive Bacteria Beta-hemolytic streptococci (Groups C, F, G) Viridans group streptococci Gram-Negative Bacteria Bordetella pertussis Legionella pneumophila Anaerobic Bacteria Prevotella bivia Peptostreptococcus species Other Bacteria Ureaplasma urealyticum

11 DESCRIPTION ZITHROMAX (azithromycin tablets, USP and azithromycin for oral suspension, USP) contain the active ingredient azithromycin, a macrolide antibacterial drug, for oral administration. 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-heptamethyl-11-[[3,4,6-trideoxy-3(dimethylamino-)-β-D-xylohexopyranosyl-]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 749.00. Azithromycin has the following structural formula: Azithromycin, as the dihydrate, is a white crystalline powder with a molecular formula of C38H72N2O12∙2H2O and a molecular weight of 785.0. ZITHROMAX tablets (azithromycin tablets, USP) is supplied as tablets containing azithromycin dihydrate equivalent to either 250 mg or 500 mg azithromycin and the following inactive ingredients: D&C Red #30 aluminum lake, dibasic calcium phosphate anhydrous, hypromellose, lactose, magnesium stearate, pregelatinized starch, sodium croscarmellose, sodium lauryl sulfate, titanium dioxide, and triacetin. ZITHROMAX for oral suspension (azithromycin for oral suspension, USP) is supplied in bottles containing azithromycin dihydrate powder equivalent to 300 mg, 600 mg, 900 mg, or 1200 mg azithromycin per bottle and the following inactive ingredients: FD&C Red#40, hydroxypropyl cellulose, sodium phosphate tribasic anhydrous, sucrose, xanthan gum, and spray dried artificial banana, cherry, and creme de vanilla flavors. After constitution, each 5 mL of suspension contains 100 mg or 200 mg of azithromycin. Chemical Structure

10 OVERDOSAGE Adverse reactions experienced at higher than recommended doses were similar to those seen at normal doses particularly nausea, diarrhea, and vomiting. In the event of overdosage, general symptomatic and supportive measures are indicated as required.

16 HOW SUPPLIED/STORAGE AND HANDLING ZITHROMAX Tablets How Supplied ZITHROMAX tablets (azithromycin tablets, USP) are supplied in the following strengths and package configurations: Tablet strength Tablet Color/Shape Tablet Markings Package Size NDC Code 250 mg (containing azithromycin dihydrate equivalent to 250 mg of azithromycin) Pink modified capsular shaped, engraved, film-coated Engraved with "PFIZER" on one side and "306" on the other Bottles of 30 NDC 0069-3060-30 Boxes of 3 (Z-PAKS ® of 6) NDC 0069-3060-75 Unit Dose package of 50 NDC 0069-3060-86 Engraved with "Pfizer" on one side and "ZTM 250" on the other Bottles of 30 NDC 0069-4061-01 Boxes of 3 (Z-PAKS ® of 6) NDC 0069-4061-75 Unit Dose package of 50 NDC 0069-4061-89 500 mg (containing azithromycin dihydrate equivalent to 500 mg of azithromycin) Pink modified capsular shaped, engraved, film coated Engraved with "Pfizer" on one side and "ZTM500" on the other Bottles of 30 NDC 0069-3070-30 Boxes of 3 (TRI-PAKSTM of 3 tablets) NDC 0069-3070-75 Storage and Handling Store ZITHROMAX tablets between 15° to 30°C (59° to 86°F). ZITHROMAX for Oral Suspension How Supplied ZITHROMAX for oral suspension (azithromycin for oral suspension, USP) after constitution contains a flavored suspension. ZITHROMAX for oral suspension is supplied to provide 100 mg/5 mL or 200 mg/5 mL suspension in bottles as follows: Azithromycin contents per bottle NDC 300 mg 0069-3110-19 600 mg 0069-3120-19 900 mg 0069-3130-19 1200 mg 0069-3140-19 Constitution instructions are described for each bottle type elsewhere in the prescribing information [see Dosage and Administration (2) ] . Storage and Handling Store dry powder below 30°C (86°F). Store constituted suspension between 5° to 30°C (41° to 86°F) and discard when full dosing is completed [see Dosage and Administration (2) ] .