Pharmacokinetics of azithromycin in trachoma patients - Serum and tear levels

Objective: To determine the effectiveness of single-dose oral azithromycin in the treatment of Chlamydia trachomatis through monitoring of tear and serum levels. Design: Nonrandomized, clinical trial. Participants: Fourteen school-age children with active trachoma (one failed to complete the study). Intervention: A single dose of azithromycin (20 mg/kg) was administered orally to 14 patients, and tear and serum levels were determined with high-performance liquid chromatography at 12, 24, 48, 72, 96, 120, and 144 hours after administration. Main Outcome Measures: Azithromycin levels in tears and serum. Results: Peak levels of 1.53 mu g/ml (standard deviation [SD] +/- 0.94) and 0.15 mu g/ml (SD +/- 0.04) were obtained al 12 hours in both tears and serum, gradually decreasing over 144 hours. All patients were disease-free by 6 months. Conclusions: Levels of azithromycin in patients with trachoma were found to be within minimum inhibitory concentration range for Chlamydia trachomatis (0.03-0.25 mu g/ml) throughout the monitored period of 6 days.