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 2-5, 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 1-5, 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.
In two clinical studies, azithromycin for oral suspension was dosed at 10 mg/kg on day 1, followed by 5 mg/kg on days 2 through 5 in two groups of pediatric patients (aged 1 to 5 years and 5 to 15 years, respectively). The mean pharmacokinetic parameters on day 5 were Cmax = 0.216 mcg/mL, Tmax = 1.9 hour, and AUC0-24 = 1.822 mcg·hr/mL for the 1 to 5-year-old group and were Cmax = 0.383 mcg/mL, Tmax = 2.4 hour, and AUC0-24 = 3.109 mcg·hr/mL for the 5 to 15-year-old group.
In another study, 33 pediatric patients received doses of 12 mg/kg/day (maximum daily dose 500 mg) for 5 days, of whom 31 patients were evaluated for azithromycin pharmacokinetics following a low fat breakfast. In this study, azithromycin concentrations were determined over a 24 hour period following the last daily dose. Patients weighing above 41.7 kg received the maximum adult daily dose of 500 mg. Seventeen patients (weighing 41.7 kg or less) received a total dose of 60 mg/kg. The following table shows pharmacokinetic data in the subset of pediatric patients who received a total dose of 60 mg/kg.
Pharmacokinetic Parameter [mean (SD)] | 5-Day Regimen (12 mg/kg for 5 days) |
N | 17 |
Cmax (mcg/mL) | 0.5 (0.4) |
Tmax (hr) | 2.2 (0.8) |
AUC0-24 (mcg∙hr/mL) | 3.9 (1.9) |
Single dose pharmacokinetics of azithromycin in pediatric patients given doses of 30 mg/kg have not been studied. [see Dosage and Administration (2)]
Drug interaction studies were performed with azithromycin and other drugs likely to be co-administered. The effects of co-administration of azithromycin on the pharmacokinetics of other drugs are shown in Table 1 and the effects of other drugs on the pharmacokinetics of azithromycin are shown in Table 2.
Co-administration of azithromycin at therapeutic doses had a modest effect on the pharmacokinetics of the drugs listed in Table 1. No dosage adjustment of drugs listed in Table 1 is recommended when co-administered with azithromycin.
Co-administration of azithromycin with efavirenz or fluconazole had a modest effect on the pharmacokinetics of azithromycin. Nelfinavir significantly increased the Cmax and AUC of azithromycin. No dosage adjustment of azithromycin is recommended when administered with drugs listed in Table 2. [see Drug Interactions (7.3)]
Table 1. Drug Interactions: Pharmacokinetic Parameters for Co-administered Drugs in the Presence of Azithromycin |
Co-administered Drug | Dose of Co-administered Drug | Dose of Azithromycin | n | Ratio (with/without azithromycin) of Co-administered Drug Pharmacokinetic Parameters (90% CI); No Effect = 1.00 |
Mean Cmax | Mean AUC |
Atorvastatin | 10 mg/day for 8 days | 500 mg/day orally on days 6-8 | 12 | 0.83 (0.63 to 1.08) | 1.01 (0.81 to 1.25) |
Carbamazepine | 200 mg/day for 2 days, then 200 mg twice a day for 18 days | 500 mg/day orally for days 16-18 | 7 | 0.97 (0.88 to 1.06) | 0.96 (0.88 to 1.06) |
Cetirizine | 20 mg/day for 11 days | 500 mg orally on day 7, then 250 mg/day on days 8-11 | 14 | 1.03 (0.93 to 1.14) | 1.02 (0.92 to 1.13) |
Didanosine | 200 mg orally twice a day for 21 days | 1200 mg/day orally on days 8-21 | 6 | 1.44 (0.85 to 2.43) | 1.14 (0.83 to 1.57) |
Efavirenz | 400 mg/day for 7 days | 600 mg orally on day 7 | 14 | 1.04* | 0.95* |
Fluconazole | 200 mg orally single dose | 1200 mg orally single dose | 18 | 1.04 (0.98 to 1.11) | 1.01 (0.97 to 1.05) |
Indinavir | 800 mg three times a day for 5 days | 1200 mg orally on day 5 | 18 | 0.96 (0.86 to 1.08) | 0.90 (0.81 to 1.00) |
Midazolam | 15 mg orally on day 3 | 500 mg/day orally for 3 days | 12 | 1.27 (0.89 to 1.81) | 1.26 (1.01 to 1.56) |
Nelfinavir | 750 mg three times a day for 11 days | 1,200 mg orally on day 9 | 14 | 0.90 (0.81 to 1.01) | 0.85 (0.78 to 0.93) |
Sildenafil | 100 mg on days 1 and 4 | 500 mg/day orally for 3 days | 12 | 1.16 (0.86 to 1.57) | 0.92 (0.75 to 1.12) |
Theophylline | 4 mg/kg IV on days 1, 11, 25 | 500 mg orally on day 7, 250 mg/day on days 8-11 | 10 | 1.19 (1.02 to 1.40) | 1.02 (0.86 to 1.22) |
Theophylline | 300 mg orally twice a day for 15 days | 500 mg orally on day 6, then 250 mg/day on days 7-10 | 8 | 1.09 (0.92 to 1.29) | 1.08 (0.89 to 1.31) |
Triazolam | 0.125 mg on day 2 | 500 mg orally on day 1, then 250 mg/day on day 2 | 12 | 1.06* | 1.02* |
Trimethoprim/ Sulfamethoxazole | 160 mg/800 mg/day orally for 7 days | 1200 mg orally on day 7 | 12 | 0.85 (0.75 to 0.97) / 0.90 (0.78 to 1.03) | 0.87 (0.80 to 0.95) / 0.96 (0.88 to 1.03) |
Zidovudine | 500 mg/day orally for 21 days | 600 mg/day orally for 14 days | 5 | 1.12 (0.42 to 3.02) | 0.94 (0.52 to 1.70) |
Zidovudine | 500 mg/day orally for 21 days | 1200 mg/day orally for 14 days | 4 | 1.31 (0.43 to 3.97) | 1.30 (0.69 to 2.43) |
* - 90% Confidence interval not reported |
Table 2. Drug Interactions: Pharmacokinetic Parameters for Azithromycin in the Presence of Co-administered Drugs.[see Drug Interactions (7)] |
Co-administered Drug | Dose of Co-administered Drug | Dose of Azithromycin | n | Ratio (with/without co-administered drug) of Azithromycin Pharmacokinetic Parameters (90% CI); No Effect = 1.00 |
Mean Cmax | Mean AUC |
Efavirenz | 400 mg/day for 7 days | 600 mg orally on day 7 | 14 | 1.22 (1.04 to 1.42) | 0.92* |
Fluconazole | 200 mg orally single dose | 1,200 mg orally single dose | 18 | 0.82 (0.66 to 1.02) | 1.07 (0.94 to 1.22) |
Nelfinavir | 750 mg three times a day for 11 days | 1,200 mg orally on day 9 | 14 | 2.36 (1.77 to 3.15) | 2.12 (1.80 to 2.50) |
* - 90% Confidence interval not reported |