Chlamydia in pregnancy: a randomized trial of azithromycin and erythromycin

Obstet Gynecol. 1998 Feb;91(2):165-8. doi: 10.1016/s0029-7844(97)00586-3.


Objective: To determine side effect profiles and cure rates of azithromycin compared with erythromycin in the treatment of chlamydial cervicitis complicating pregnancy.

Methods: Pregnant patients with positive DNA antigen assays for Chlamydia trachomatis were randomized to either azithromycin, 1 g oral slurry in a single dose, or erythromycin, 500 mg every 6 hours for 7 days. Repeat assays were planned for 3 weeks after therapy. Side effects, compliance, and treatment efficacy were assessed.

Results: One hundred six women were enrolled, and eighty-five women completed the protocol. Significantly fewer gastrointestinal side effects were noted in the azithromycin group than in the erythromycin group (11.9% versus 58.1%, P < or = .01). Enhanced compliance was noted with azithromycin, because it was given in a single observed dose. Similar treatment efficacy was noted between azithromycin and erythromycin (88.1% versus 93.0%, P > .05).

Conclusion: Compared with erythromycin, azithromycin is associated with significantly fewer gastrointestinal side effects in pregnancy. This association, along with the ease of administration and similar efficacy, suggests that azithromycin should be considered for the initial treatment of chlamydial cervicitis in pregnancy.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Anti-Bacterial Agents / adverse effects
  • Anti-Bacterial Agents / therapeutic use*
  • Azithromycin / adverse effects
  • Azithromycin / therapeutic use*
  • Chlamydia Infections / drug therapy*
  • Chlamydia trachomatis*
  • Erythromycin / adverse effects
  • Erythromycin / therapeutic use*
  • Female
  • Humans
  • Pregnancy
  • Pregnancy Complications, Infectious / drug therapy*
  • Uterine Cervicitis / drug therapy*


  • Anti-Bacterial Agents
  • Erythromycin
  • Azithromycin