PHARMACOKINETIC AND CLINICAL STUDIES ON AZITHROMYCIN IN CHILDREN

Azithromycin (AZM) is a new oral macrolide antibiotic drug. AZM either in 10% finegranules form or in 100 mg capsule form was studied for its pharmacokinetics and treatment efficacy in pediatric patients with various infections. 1. Pharmacokinetics Plasma and urine samples were collected from four patients with pharyngitis and post-dosing drug levels were determined. The drug was given once daily at 10 mg/kg body weight for 3 days. The drug concentrations found in plasma at 96 hours after the first dosing (48 hours after the final dosing) lay in a range of 0.02 and 0.04 μg/ml and in urine at 120 hours after the first dosing (72 hours after the final dosing) in a range between 3.2 and 7.7 μg/ml. AZM was found in two patients but no effect was o bserved on blood levels of theophylline determined between 48 and 96 hours after the first dosing in the treatment of underlying bronchial asthma. 2. Clinical study results Clinical studies of AZM was carried out in 25 pediatric patients with bacterial infections that mainly affected the respiratory tract. The patients received either 10% fine granules at 10 or 20 mg/kg body weight or 100 mg capsules at 10 mg/kg body weight once daily over 3 to 6 days. The drug was found markedly effective in six patients, moderately effective in thirteen patients, while the investigators could not assess the drug efficacy in six patients. Although no side effect was reported in the study, two patients experienced slight decrease in WBC.