Objective: To determine the effectiveness of single-dose oral azithrom
ycin in the treatment of Chlamydia trachomatis through monitoring of t
ear and serum levels. Design: Nonrandomized, clinical trial. Participa
nts: Fourteen school-age children with active trachoma (one failed to
complete the study). Intervention: A single dose of azithromycin (20 m
g/kg) was administered orally to 14 patients, and tear and serum level
s were determined with high-performance liquid chromatography at 12, 2
4, 48, 72, 96, 120, and 144 hours after administration. Main Outcome M
easures: 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 (S
D +/- 0.04) were obtained al 12 hours in both tears and serum, gradual
ly decreasing over 144 hours. All patients were disease-free by 6 mont
hs.Conclusions: Levels of azithromycin in patients with trachoma were
found to be within minimum inhibitory concentration range for Chlamydi
a trachomatis (0.03-0.25 mu g/ml) throughout the monitored period of 6
days.