Azithromycin

Zithromax

01Approved uses

• Acute bacterial exacerbations of chronic bronchitis 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.

02Forms and strengths

• ZITHROMAX tablets 250 mg and 500 mg
• ZITHROMAX for oral suspension 100 mg/5 mL and 200 mg/5 mL

03How it is taken

• Recommended Dosage for Adult Patients
• 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
• 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.

04Must not be used when

• Patients with known hypersensitivity to azithromycin, erythromycin, any macrolide or ketolide drug.
• Patients with a history of cholestatic jaundice/hepatic dysfunction associated with prior use of azithromycin.

05Interactions

• Nelfinavir: Close monitoring for known adverse reactions of azithromycin, such as liver enzyme abnormalities and hearing impairment, is warranted.
• Warfarin: Use with azithromycin may increase coagulation times; monitor prothrombin time.

06Warnings and precautions

• Serious (including fatal) allergic and skin reactions: Discontinue ZITHROMAX if reaction occurs.
• Hepatotoxicity: Severe, and sometimes fatal, hepatotoxicity has been reported. Discontinue ZITHROMAX immediately if signs and symptoms of hepatitis occur.
• 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.
• 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.
• 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 ZITHROMAX.
• Clostridioides difficile -Associated Diarrhea: Evaluate patients if diarrhea occurs.
• ZITHROMAX may exacerbate muscle weakness in persons with myasthenia gravis.
• patients with known prolongation of the QT interval, a history of torsades de pointes, congenital long QT syndrome, bradyarrhythmias or uncompensated heart failure

07Common side effects

• Most common adverse reactions are diarrhea (5 to 14%), nausea (3 to 18%), abdominal pain (3 to 7%), or vomiting (2 to 7%).
• 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.
• 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.

08Pregnancy

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).

09How it acts

Azithromycin is a macrolide antibacterial drug. 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.

This section reports the approved product information. The wording is condensed from the regulator's own summary, and the full document is linked under Sources.