Randomized Trial of Erythromycin and Azithromycin for Treatment of Chlamydial Infection in Pregnancy

Objective: The purpose of this study was to compare erythromycin and azithromycin in the treatment of chlamydial cervicitis during pregnancy with regard to efficacy, side effects, and compliance. Methods: In a prospective manner, 48 pregnant patients with cervical chlamydial infections diagnosed by routine screening tests were randomly assigned to receive either erythromycin, 500 mg q.i.d. for 7 days (N = 24), or azithromycin, 1 g as a one-time dose (N = 24). All sexual partners were given prescriptions for doxycycline, 100 mg b.i.d. for 7 days. The treatment efficacy was assessed by follow-up chlamydia testing 3 weeks after the therapy was completed. The side effects, intolerance to therapy, and overall compliance were evaluated by means of a standardized posttreatment questionnaire. Results: There was no significant difference in cure rates noted between the erythromycin group and the azithromycin group (77% vs. 91%, respectively; P = 0.24). Gastrointestinal side effects were reported more frequently among patients treated with erythromycin compared with patients treated with azithromycin (45% vs. 17%, respectively; P = 0.004). The patients who received erythromycin reported intolerance to therapy secondary to side effects more frequently than patients who received azithromycin (23% vs. 4%, respectively; P = 0.07). Furthermore, the patients in the azithromycin group were more likely to complete their course of therapy as prescribed than the patients in the erythromycin group (100% vs. 61%, respectively; P = 0.002). Conclusions: Azithromycin is efficacious and well tolerated for the treatment of chlamydial cervicitis in pregnancy. Erythromycin, though efficacious, is poorly tolerated, as demonstrated by the number of patients reporting significant side effects during the course of therapy. Since the cost of azithromycin is comparable to that of generic erythromycin, the present study supports the use of azithromycin as an alternative to erythromycin for the treatment of chlamydial cervicitis in pregnancy.