Comparing ceftriaxone plus azithromycin or doxycycline for pelvic inflammatory disease: a randomized controlled trial.

Objective: To evaluate the equivalence of ceftriaxone plus doxycycline or azithromycin for cases of mild pelvic inflammatory disease (PID).

Methods: Patients with PID received an intramuscular injection of 250 mg of ceftriaxone, and were randomly assigned to receive 200 mg/d of doxycycline for 2 weeks, or 1 g of azithromycin per week, for 2 weeks. The degree of pain was assessed on days 2, 7, and 14 and clinical cure was assessed on day 14.

Results: From 133 patients eligible for the study, 13 were excluded for having conditions other than PID, 11 were lost on follow-up, and three had oral intolerance to the antibiotics, yielding 106 for protocol analysis. No significant difference was observed regarding the degree of pain between the doxycycline and azithromycin groups. Clinical cure per protocol was 98.2% (56 of 57; 95% confidence interval [CI], 0.9-0.99) with azithromycin, and 85.7% (42 of 49; 95% CI, 0.72-0.93) with doxycycline (P=0.02). In a modified intention to treat analysis, clinical cure was 90.3% (56 of 62; 95% CI, 0.80-0.96) with azithromycin, and 72.4% (42 of 58; 95% CI, 0.58-0.82) with doxycycline (P=.01); a relative risk of 0.35, and a number needed to treat of six for benefit with azithromycin.

Conclusion: When combined with ceftriaxone, 1g of azithromycin weekly for 2 weeks is equivalent to ceftriaxone plus a 14-day course of doxycycline for treating mild PID.