AZITHROMYCIN: 17,553 Adverse Event Reports & Safety Profile

ZITHROMAX (azithromycin tablets and azithromycin for oral suspension) 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-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 749.00. 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 is supplied as tablets containing azithromycin dihydrate equivalent to either 250 mg or 500 mg azithromycin and the following inactive ingredients: dibasic calcium phosphate anhydrous, pregelatinized starch, sodium croscarmellose, magnesium stearate, sodium lauryl sulfate, hypromellose, lactose, titanium dioxide, triacetin, and D&C Red #30 aluminum lake. ZITHROMAX for oral suspension 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: sucrose; sodium phosphate, tribasic, anhydrous; hydroxypropyl cellulose; xanthan gum; FD&C Red #40; and spray dried artificial cherry, creme de vanilla, and banana flavors. After constitution, each 5 mL of suspension contains 100 mg or 200 mg of azithromycin.

Chemical

Structure

INDICATIONS AND USAGE Azithromycin for oral suspension USP is indicated for the treatment of patients with mild to moderate infections (pneumonia: see WARNINGS ) caused by susceptible strains of the designated microorganisms in the specific conditions listed below. As recommended dosages, durations of therapy and applicable patient populations vary among these infections, please see DOSAGE AND ADMINISTRATION for specific dosing recommendations.

Adults

Acute bacterial exacerbations of chronic obstructive pulmonary disease 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. NOTE: Azithromycin should not be used 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 nosocomially acquired 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). Pharyngitis/tonsillitis caused by Streptococcus pyogenes as an alternative to first-line therapy in individuals who cannot use first-line therapy. NOTE: Penicillin by the intramuscular route is the usual drug of choice in the treatment of Streptococcus pyogenes infection and the prophylaxis of rheumatic fever. Azithromycin for oral suspension USP is often effective in the eradication of susceptible strains of Streptococcus pyogenes from the nasopharynx. Because some strains are resistant to azithromycin for oral suspension USP, susceptibility tests should be performed when patients are treated with azithromycin for oral suspension USP. Data establishing efficacy of azithromycin in subsequent prevention of rheumatic fever are not available. Uncomplicated skin and skin structure infections due to Staphylococcus aureus, Streptococcus pyogenes, or Streptococcus agalactiae. Abscesses usually require surgical drainage. 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. Azithromycin for oral suspension USP, at the recommended dose, should not be relied upon to treat syphilis. Antimicrobial agents used in high doses for short periods of time to treat non-gonococcal urethritis may mask or delay the symptoms of incubating syphilis. All patients with sexually-transmitted urethritis or cervicitis should have a serologic test for syphilis and appropriate cultures for gonorrhea performed at the time of diagnosis. Appropriate antimicrobial therapy and follow-up tests for these diseases should be initiated if infection is confirmed. Appropriate culture and susceptibility tests should be performed before treatment to determine the causative organism and its susceptibility to azithromycin, USP. Therapy with azithromycin for oral suspension USP 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 oral suspension USP and other antibacterial drugs, azithromycin for oral suspension USP 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.

Pediatric Patients

See PRECAUTIONS, Pediatric Use and CLINICAL STUDIES, Pediatric Patients. Acute otitis media caused by Haemophilus influenzae, Moraxella catarrhalis or Streptococcus pneumoniae. (For specific dosage recommendation, see DOSAGE AND ADMINISTRATION .) Community-acquired pneumonia due to Chlamydophila pneumoniae, Haemophilus influenzae, Mycoplasma pneumoniae or Streptococcus pneumoniae in patients appropriate for oral therapy. (For specific dosage recommendation, see DOSAGE AND ADMINISTRATION .) NOTE: Azithromycin should not be used in pediatric 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 nosocomially acquired infections, patients with known or suspected bacteremia, patients requiring hospitalization, or patients with significant underlying health problems that may compromise their ability to respond to their illness (including immunodeficiency or functional asplenia). Pharyngitis/tonsillitis caused by Streptococcus pyogenes as an alternative to first-line therapy in individuals who cannot use first-line therapy. (For specific dosage recommendation, see DOSAGE AND ADMINISTRATION .) NOTE: Penicillin by the intramuscular route is the usual drug of choice in the treatment of Streptococcus pyogenes infection and the prophylaxis of rheumatic fever. Azithromycin for oral suspension USP is often effective in the eradication of susceptible strains of Streptococcus pyogenes from the nasopharynx. Because some strains are resistant to azithromycin for oral suspension USP, susceptibility tests should be performed when patients are treated with azithromycin for oral suspension USP. Data establishing efficacy of azithromycin in subsequent prevention of rheumatic fever are not available. Appropriate culture and susceptibility tests should be performed before treatment to determine the causative organism and its susceptibility to azithromycin. Therapy with azithromycin for oral suspension USP may be initiated before results of these tests are known; once the results become available, antimicrobial therapy should be adjusted accordingly.

AND ADMINISTRATION

• 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.

• 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 Adult Patients <span class="opacity-50 text-xs">[see Indications and Usage ( 1.1 ) and Clinical Pharmacology ( 12.3 )]</span> Infection DUE TO THE INDICATED ORGANISMS <span class="opacity-50 text-xs">[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 Azithromycin tablets can be taken with or without food.

2.2 Pediatric Patients 1 Infection DUE TO THE INDICATED ORGANISMS [see Indications and Usage ( 1.2 )]</span>

Recommended

Dose/Duration of Therapy 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. 1 see dosing tables below for maximum doses evaluated by indication Azithromycin for oral suspension can be taken with or without food. 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 PEDIATRIC DOSAGE GUIDELINES FOR OTITIS MEDIA, ACUTE BACTERIAL SINUSITIS, AND COMMUNITY-ACQUIRED PNEUMONIA (Age 6 months and above, [ see Error! Hyperlink reference not valid. ] ) Based on Body Weight OTITIS MEDIA AND COMMUNITY-ACQUIRED PNEUMONIA: (5-Day Regimen)* 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 Day 1 Days 2-5 5 2.5 mL; (½ tsp) 1.25 mL; (¼ tsp) 7.5 mL 150 mg 10 5 mL; (1 tsp) 2.5 mL; (½ tsp) 15 mL 300 mg 20 5 mL; (1 tsp) 2.5 mL; (½ tsp) 15 mL 600 mg 30 7.5 mL; (1½ tsp) 3.75 mL; (¾ tsp) 22.5 mL 900 mg 40 10 mL; (2 tsp) 5 mL; (1 tsp) 30 mL 1200 mg 50 and above 12.5 mL; (2½ tsp) 6.25 mL; (1¼ tsp) 37.5 mL 1500 mg 1. Effectiveness of the 3-day or 1-day regimen in pediatric patients with community-acquired pneumonia has not been established. OTITIS MEDIA AND ACUTE BACTERIAL SINUSITIS: (3-Day Regimen)* Dosing Calculated on 10 mg/kg/day.

Weight

100 mg/5 mL 200 mg/5 mL Total mL per Treatment Course Total mg per Treatment Course Kg Days 1-3 Days 1-3 5 2.5 mL; (½ tsp) 7.5 mL 150 mg 10 5 mL; (1 tsp) 15 mL 300 mg 20 5 mL (1 tsp) 15 mL 600 mg 30 7.5 mL (1½ tsp) 22.5 mL 900 mg 40 10 mL (2 tsp) 30 mL 1200 mg 50 and above 12.5 mL (2½ tsp) 37.5 mL 1500 mg 1. Effectiveness of the 5-day or 1-day regimen in pediatric patients with acute bacterial sinusitis has not been established. OTITIS MEDIA: (1-Day Regimen)

Dosing

Calculated on 30 mg/kg as a single dose.

Weight

200 mg/5 mL Total mL per Treatment Course Total mg per Treatment Course Kg 1-Day Regimen 5 3.75 mL;(3/4 tsp) 3.75 mL 150 mg 10 7.5 mL;(1½ tsp) 7.5 mL 300 mg 20 15 mL;(3 tsp) 15 mL 600 mg 30 22.5 mL;(4½ tsp) 22.5 mL 900 mg 40 30 mL;(6 tsp) 30 mL 1200 mg 50 and above 37.5 mL;(7½ tsp) 37.5 mL 1500 mg The safety of re-dosing azithromycin in pediatric patients who vomit after receiving 30 mg/kg as a single dose has not been established. In clinical studies involving 487 patients with acute otitis media given a single 30 mg/kg dose of azithromycin, 8 patients who vomited within 30 minutes of dosing were re-dosed at the same total dose. Pharyngitis/Tonsillitis: The recommended dose of azithromycin for children with pharyngitis/tonsillitis is 12 mg/kg once daily for 5 days. (See chart below.) PEDIATRIC DOSAGE GUIDELINES FOR PHARYNGITIS/TONSILLITIS (Age 2 years and above, [see Use in Specific Populations ( 8.4 )] ) Based on Body Weight PHARYNGITIS/TONSILLITIS: (5-Day Regimen)

Dosing

Calculated on 12 mg/kg/day for 5 days.

Weight

200 mg/5 mL Total mL per Treatment Course Total mg per Treatment Course Kg Day 1 to 5 8 2.5 mL; (½ tsp) 12.5 mL 500 mg 17 5 mL; (1 tsp) 25 mL 1000 mg 25 7.5 mL; (1½ tsp) 37.5 mL 1500 mg 33 10 mL; (2 tsp) 50 mL 2000 mg 40 12.5 mL; (2½ tsp) 62.5 mL 2500 mg Constituting instructions for Azithromycin Oral Suspension 300, 600, 900, 1200 mg bottles. The table below indicates the volume of water to be used for constitution: Amount of water to be added Total volume after constitution (azithromycin content) Azithromycin concentration after constitution 9 mL (300 mg) 15 mL (300 mg) 100 mg/5 mL 9 mL (600 mg) 15 mL (600 mg) 200 mg/5 mL 12 mL (900 mg) 22.5 mL (900 mg) 200 mg/5 mL 15 mL (1200 mg) 30 mL (1200 mg) 200 mg/5 mL Shake well before each use. Oversized bottle provides shake space. Keep tightly closed. After mixing, store suspension at 5° to 30°C (41° to 86°F) and use within 10 days. Discard after full dosing is completed.

4 CONTRAINDICATIONS

• Patients with known hypersensitivity to azithromycin, erythromycin, any macrolide or ketolide drug. ( Error! Hyperlink reference not valid. )
• Patients with a history of cholestatic jaundice/hepatic dysfunction associated with prior use of azithromycin. ( Error! Hyperlink reference not valid. )

4.1 Hypersensitivity Azithromycin for oral suspension is contraindicated in patients with known hypersensitivity to azithromycin, erythromycin, any macrolide or ketolide drug.

4.2 Hepatic Dysfunction Azithromycin for oral suspension is contraindicated in patients with a history of cholestatic jaundice/hepatic dysfunction associated with prior use of azithromycin.

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 ( Error! Hyperlink reference not valid. )]
• Clostridioides difficile-Associated Diarrhea (CDAD) [see Warnings and Precautions ( Error! Hyperlink reference not valid. )]
• Exacerbation of Myasthenia Gravis [see Warnings and Precautions ( Error! Hyperlink reference not valid. )] Most common adverse reactions are diarrhea (5 to 14%), nausea (3 to 18%), abdominal pain (3 to 7%), or vomiting (2 to 7%). ( Error! Hyperlink reference not valid. ) To report SUSPECTED ADVERSE REACTIONS, contact Sandoz Inc. at 1-800-525-8747 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 azithromycin 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 )] .

Adults

Multiple-dose regimens: Overall, the most common treatment-related adverse reactions in adult patients receiving multiple-dose regimens of azithromycin 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 azithromycin 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 azithromycin 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 azithromycin 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 azithromycin 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.

Pediatric Patients

Single and Multiple-dose regimens: The types of adverse reactions in pediatric patients were comparable to those seen in adults, with different incidence rates for the dosage regimens recommended in pediatric patients.

Acute Otitis

Media: For the recommended total dosage regimen of 30 mg/kg, the most frequent adverse reactions (≥1%) attributed to treatment were diarrhea, abdominal pain, vomiting, nausea, and rash [see Dosage and Administration ( 2 ) and Clinical Studies ( 14.2 )] . The incidence, based on dosing regimen, is described in the table below: Dosage Regimen Diarrhea % Abdominal Pain % Vomiting % Nausea % Rash % 1-day 4.3% 1.4% 4.9% 1.0% 1.0% 3-day 2.6% 1.7% 2.3% 0.4% 0.6% 5-day 1.8% 1.2% 1.1% 0.5% 0.4% Community-Acquired Pneumonia: For the recommended dosage regimen of 10 mg/kg on Day 1 followed by 5 mg/kg on Days 2 to 5, the most frequent adverse reactions attributed to treatment were diarrhea/loose stools, abdominal pain, vomiting, nausea, and rash. The incidence is described in the table below: Dosage Regimen Diarrhea/Loose stools % Abdominal Pain % Vomiting % Nausea % Rash % 5-day 5.8% 1.9% 1.9% 1.9% 1.6% Pharyngitis/tonsillitis: For the recommended dosage regimen of 12 mg/kg on Days 1 to 5, the most frequent adverse reactions attributed to treatment were diarrhea, vomiting, abdominal pain, nausea, and headache. The incidence is described in the table below: Dosage Regimen Diarrhea % Abdominal Pain % Vomiting % Nausea % Rash % Headache % 5-day 5.4% 3.4% 5.6% 1.8% 0.7% 1.1% With any of the treatment regimens, no other adverse reactions occurred in pediatric patients treated with azithromycin with a frequency greater than 1%. Adverse reactions that occurred with a frequency of 1% or less included the following: Cardiovascular: Chest pain. Gastrointestinal: Dyspepsia, constipation, anorexia, enteritis, flatulence, gastritis, jaundice, loose stools, and oral moniliasis. Hematologic and Lymphatic: Anemia and leukopenia.

Nervous

System: Headache (otitis media dosage), hyperkinesia, dizziness, agitation, nervousness, and insomnia. General: Fever, face edema, fatigue, fungal infection, malaise, and pain. Allergic: Rash and allergic reaction. Respiratory: Cough, pharyngitis, pleural effusion, and rhinitis. Skin and Appendages: Eczema, fungal dermatitis, pruritus, sweating, urticaria, and vesiculobullous rash.

Special

Senses: Conjunctivitis.

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 reports of tongue discoloration. General: Asthenia, paresthesia, fatigue, malaise, and anaphylaxis. Genitourinary: Interstitial nephritis and acute renal failure and vaginitis. Hematopoietic: Thrombocytopenia. Liver/Biliary: Abnormal liver function, hepatitis, cholestatic jaundice, hepatic necrosis, and hepatic failure <span class="opacity-50 text-xs">[see Warnings and Precautions ( 5.2 )]</span> .

Nervous

System: Convulsions, dizziness/vertigo, headache, somnolence, hyperactivity, nervousness, agitation, and syncope. Psychiatric: Aggressive reaction and anxiety. Skin/Appendages : Pruritus 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 Adults Clinically significant abnormalities (irrespective of drug relationship) occurring during the clinical trials were reported as follows: with an incidence of greater than 1%: decreased hemoglobin, hematocrit, lymphocytes, neutrophils, and blood glucose; elevated serum creatine phosphokinase, potassium, ALT, GGT, AST, BUN, creatinine, blood glucose, platelet count, lymphocytes, neutrophils, and eosinophils; with an incidence of less than 1%: leukopenia, neutropenia, decreased sodium, potassium, platelet count, elevated monocytes, basophils, bicarbonate, serum alkaline phosphatase, bilirubin, LDH, and phosphate. The majority of subjects with elevated serum creatinine also had abnormal values at baseline. When follow-up was provided, changes in laboratory tests appeared to be reversible. In multiple-dose clinical trials involving more than 5000 patients, four patients discontinued therapy because of treatment-related liver enzyme abnormalities and one because of a renal function abnormality.

Pediatric Patients

One, Three, and Five Day Regimens Laboratory data collected from comparative clinical trials employing two 3-day regimens (30 mg/kg or 60 mg/kg in divided doses over 3 days), or two 5-day regimens (30 mg/kg or 60 mg/kg in divided doses over 5 days) were similar for regimens of azithromycin and all comparators combined, with most clinically significant laboratory abnormalities occurring at incidences of 1 to 5%. Laboratory data for patients receiving 30 mg/kg as a single dose were collected in one single center trial. In that trial, an absolute neutrophil count between 500 to 1500 cells/mm 3 was observed in 10/64 patients receiving 30 mg/kg as a single dose, 9/62 patients receiving 30 mg/kg given over 3 days, and 8/63 comparator patients. No patient had an absolute neutrophil count <500 cells/mm 3 . In multiple-dose clinical trials involving approximately 4700 pediatric patients, no patients discontinued therapy because of treatment-related laboratory abnormalities.

AND PRECAUTIONS Serious (including fatal) allergic and skin reactions. Discontinue azithromycin for injection and initiate appropriate therapy if reaction occurs. ( 5.1 ) Hepatotoxicity: Severe and sometimes fatal, hepatoxicity has been reported. Discontinue azithromycin for injection immediately if signs and symptoms of hepatitis occur. ( 5.2 )

Infantile Hypertrophic Pyloric

Stenosis (IHPS): Following the use of azithromycin in neonates (treatment up to 42 days of life), IHPS has been reported. Direct parents and caregivers to contact their physician if vomiting or irritability with feeding occurs. ( 5.3 ) Prolongation of QT interval and cases of torsades de pointes have been reported. This risk which can be fatal should be considered in patients with certain cardiovascular disorders including known QT prolongation or history torsades de pointes, those with proarrhythmic conditions, and with other drugs that prolong the QT interval. ( 5.4 )

Cardiovascular

Death: Some observational studies have shown an approximately two-fold increased short-term potential risk of acute cardiovascular death in adults exposed to azithromycin relative to other antibacterial drugs, including amoxicillin. Consider balancing this potential risk with treatment benefits when prescribing azithromycin for injection. ( 5.5 ) Clostridioides difficile -Associated Diarrhea: Evaluate patients if diarrhea occurs. ( 5.6 ) Azithromycin for injection may exacerbate muscle weakness in persons with myasthenia gravis. ( 5.7 )

5.1 Hypersensitivity Serious allergic reactions, including angioedema, anaphylaxis, and dermatologic reactions including Acute Generalized Exanthematous Pustulosis (AGEP), Stevens-Johnson Syndrome and toxic epidermal necrolysis have been reported in patients on azithromycin therapy <span class="opacity-50 text-xs">[see Contraindications ( 4.1 )]</span>. Fatalities have been reported. Cases of Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) have also been reported. 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 the allergic symptoms may reappear after symptomatic therapy has been discontinued.

5.2 Hepatotoxicity Abnormal liver function, hepatitis, cholestatic jaundice, hepatic necrosis, and hepatic failure have been reported, some of which have resulted in death. Discontinue azithromycin immediately if signs and symptoms of hepatitis occur.

5.3 Infantile Hypertrophic Pyloric Stenosis (IHPS) Following the use of azithromycin in neonates (treatment up to 42 days of life), IHPS has been reported. Direct parents and caregivers to contact their physician if vomiting or irritability with feeding occurs.

5.4 QT Prolongation Prolonged cardiac repolarization and QT interval, imparting a risk of developing cardiac arrhythmia and torsades de pointes, have been seen with treatment with macrolides, including azithromycin. Cases of torsades de pointes have been spontaneously reported during postmarketing surveillance in patients receiving azithromycin. Providers should consider the risk of QT prolongation, which can be fatal when weighing the risks and benefits of azithromycin for at-risk groups including: patients with known prolongation of the QT interval, a history of torsades de pointes, congenital long QT syndrome, bradyarrhythmias or uncompensated heart failure patients on drugs known to prolong the QT interval patients with ongoing proarrhythmic conditions such as uncorrected hypokalemia or hypomagnesemia, clinically significant bradycardia, and in patients receiving Class IA (quinidine, procainamide) or Class III (dofetilide, amiodarone, sotalol) antiarrhythmic agents. Elderly patients may be more susceptible to drug-associated effects on the QT interval.

5.5 Cardiovascular Death Some observational studies have shown an approximately two-fold increased short-term potential risk of acute cardiovascular death in adults exposed to azithromycin relative to other antibacterial drugs, including amoxicillin. The five-day cardiovascular mortality observed in these studies ranged from 20 to 400 per million azithromycin treatment courses. This potential risk was noted to be greater during the first five days of azithromycin use and does not appear to be limited to those patients with preexisting cardiovascular diseases. The data in these observational studies are insufficient to establish or exclude a causal relationship between acute cardiovascular death and azithromycin use. Consider balancing this potential risk with treatment benefits when prescribing azithromycin for injection.

5.6 Clostridioides Difficile -Associated Diarrhea Clostridioides difficile associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including azithromycin for injection, 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 antibacterial therapy and may require colectomy. CDAD must be considered in all patients who present with diarrhea following antibacterial 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 antibacterial use not directed against C. difficile may need to be discontinued. Appropriate fluid and electrolyte management, protein supplementation, antibacterial treatment of C. difficile , and surgical evaluation should be instituted as clinically indicated.

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

5.8 Infusion Site Reactions Azithromycin for injection should be reconstituted and diluted as directed and administered as an intravenous infusion over not less than 60 minutes <span class="opacity-50 text-xs">[see Dosage and Administration ( 2 )]</span> . Local IV 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 was given over 1 hour (2 mg/mL as 250 mL infusion) or over 3 hours (1 mg/mL as 500 mL infusion) <span class="opacity-50 text-xs">[see Adverse Reactions ( 6 )]</span> . All volunteers who received infusate concentrations above 2.0 mg/mL experienced local IV site reactions and, therefore, higher concentrations should be avoided.

5.9 Development of Drug-Resistant Bacteria Prescribing azithromycin in the absence of a proven or strongly suspected bacterial infection is unlikely to provide benefit to the patient and increases the risk of the development of drug‑resistant bacteria.

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 IV 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 IV site reactions and, therefore, higher concentrations should be avoided. 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 co-administered 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/m 2 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 to 85 years old) were similar to those in younger volunteers (18 to 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. Elderly patients may be more susceptible to development of torsades de pointes arrhythmia than younger patients (see WARNINGS ). 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.

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 IV 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 IV site reactions and, therefore, higher concentrations should be avoided. 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 co-administered 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/m 2 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 to 85 years old) were similar to those in younger volunteers (18 to 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. Elderly patients may be more susceptible to development of torsades de pointes arrhythmia than younger patients (see WARNINGS ). 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.

Drug Interactions Coadministration 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 postmarketing 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 coadministered (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. Coadministration 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 the above 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 concentrations.