In clinical trials, most of the reported adverse effects were mild to moderate in severity and were reversible upon discontinuation of the drug. Potentially serious adverse effects of angioedema and cholestatic jaundice were reported rarely. 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 effects. In adults given 500 mg/day for 3 days, the discontinuation rate due to treatment-related adverse effects 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 effects was approximately 1%. Most of the adverse effects leading to discontinuation were related to the gastrointestinal tract, e.g., nausea, vomiting, diarrhea, or abdominal pain.
Multiple-dose regimen: Overall, the most common treatment-related adverse effects in adult patients receiving multiple-dose regimens of Azithromycin were related to the gastrointestinal system with diarrhea/loose stools (4-5%), nausea (3%) and abdominal pain (2-3%) being the most frequently reported.
No other treatment-related adverse effects occurred in patients on the multiple-dose regimens of Azithromycin with a frequency greater than 1%. Adverse effects that occurred with a frequency of 1% or less included the following: Cardiovascular:
Palpitations, chest pain.
Dyspepsia, flatulence, vomiting, melena and cholestatic jaundice.
Monilia, vaginitis and nephritis.
Dizziness, headache, vertigo and somnolence.
Rash, pruritus, photosensitivity and angioedema.
Single 1-gram dose regimen: Overall, the most common side effects 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 effects that occurred in patients on the single one-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 effects in patients receiving a single 2-gram dose of azithromycin were related to the gastrointestinal system. Adverse effects 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.
Single and Multiple-dose regimens: The types of side effects 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 side effects (≥1%) attributed to treatment were diarrhea, abdominal pain, vomiting, nausea and rash. Side effects that occurred with a frequency of 1% or less included the following: Cardiovascular:
Dyspepsia, constipation, anorexia, enteritis, flatulence, gastritis, jaundice, loose stools and oral moniliasis.
Hematologic and Lymphatic:
Anemia and leukopenia.
Headache (otitis media dosage), hyperkinesia, dizziness, agitation, nervousness and insomnia.
Fever, face edema, fatigue, fungal infection, malaise and pain.
Rash and allergic reaction.
Cough increased, pharyngitis, pleural effusion and rhinitis.
Skin and Appendages:
Eczema, fungal dermatitis, pruritus, sweating, urticaria and vesiculobullous rash.