Erythromycin for Persistent or Recurrent Nongonococcal Urethritis: A Randomized, Placebo-Controlled Trial

Objective: To evaluate the efficacy of a 3-week regimen of erythromycin for treatment of persistent or recurrent nongonococcal urethritis in men.

Design: A prospective, randomized, double-blind trial with follow-up at 2, 4, and 8 weeks after enrollment.

Patients: Seventy-seven evaluable men with objective evidence of nongonococcal urethritis (36 in the erythromycin group and 41 in the placebo group) with a mean age of 28 years, a median duration of urethritis of 3 months, and a median number of three previous antimicrobial regimens.

Intervention: Erythromycin, 500 mg, or placebo four times daily for 3 weeks.

Results: After 2 weeks of treatment, urethral symptoms resolved in 13 of 25 erythromycin-treated patients compared with 8 of 34 placebo-treated patients (P = 0.03). Erythromycin also resulted in more frequent resolution of urethral discharge and leukocytosis at all visits compared with placebo but these differences were not statistically significant. First-voided urine leukocyte counts decreased, however, by a median of 89% (95% CI, -96% to -67%) in the erythromycin group compared with 23% (CI, -73% to 83%) in the placebo group after treatment (P = 0.02 for the difference in changes). Further, in men with prostatic inflammation, urinary leukocyte counts decreased by a median of 94% (CI, -99% to -83%) after treatment in erythromycin-treated patients compared with a 46% increase (CI, -57% to 290%) in placebo-treated patients (P = 0.0003 for the difference in changes).

Conclusion: A 3-week regimen of erythromycin was more effective than placebo in improving symptoms and in reducing pyuria in men with persistent or recurrent nongonococcal urethritis, especially among men with prostatic inflammation.