A preliminary study of clarithromycin versus doxycycline in the treatment of nongonococcal urethritis and mucopurulent cervicitis.

In a comparison of drug safety and efficacy, 40 adult outpatients with clinical signs and symptoms of nongonococcal urethritis or mucopurulent cervicitis were treated with either clarithromycin 250 mg or doxycycline 100 mg twice/day for 7 days. Clinical and laboratory evaluations were repeated during, at the end, and 3 weeks after the completion of therapy. Isolation and susceptibility tests of Chlamydia and Mycoplasma isolates were performed at each visit. All but one patient who received doxycycline were clinically cured or improved at the end of treatment. Two (10%) patients who received clarithromycin and three (15%) who received doxycycline had clinical relapses of the infection. All isolates of Chlamydia trachomatis were eradicated and did not recur in both groups. Doxycycline was more effective than clarithromycin in eradicating Ureaplasma urealyticum (p < 0.01). Both groups reported a high frequency of minor adverse effects, but no patient discontinued therapy. Overall, clarithromycin was clinically safe and effective treatment in patients with nongonococcal urethritis and mucopurulent cervicitis.