Comparative efficacy of clindamycin versus erythromycin in eradication of antenatal Chlamydia trachomatis

Antenatal Chlamydia trachomatis infections are associated with both maternal and neonatal morbidity. Erythromycin, the only drug recommended for treatment during pregnancy, is often poorly tolerated, thus preventing successful cure. We have done a prospective, randomized, double-blind, placebo-controlled trial to compare the efficacy of clindamycin with that of erythromycin base in eradication of antenatal chlamydia. A total of 126 patients with documented cervical infection were enrolled before 24 weeks' gestation to receive clindamycin (450 mg), erythromycin (333 mg), or placebo orally four times daily for 14 days. Partners received doxycycline, 100 mg, twice daily for 7 days. Both clindamycin and erythromycin were effective agents with cure rates of 92.7% and 83.8%, respectively. Erythromycin therapy was associated with significantly more gastrointestinal complaints than was placebo therapy (23.1% (9/39) vs. 2.4% (1/41), p less than 0.02) whereas clindamycin was not. Patients who experienced side effects were more likely to be poorly compliant (p less than 0.03) and patients with moderate-to-good compliance were more likely to be cured than were women who were poorly compliant (p less than 0.002). Results of test of cure cultures performed immediately on completion of therapy did not differ significantly from those taken 4 weeks later.