Low Cure Rates for Standard CDC Recommended Treatment for NGU: Results From a Double Blind Randomized Trial

Manhart, Lisa

Wednesday, March 14, 2012: 4:50 PM

Regency

Lisa Manhart, PhD¹, Catherine M. Wetmore, MPH, PhD², M. Sylvan Lowens, PA³, Danny V. Colombara, MPH⁴, Christine Khosropour, MPH⁴, Matthew R. Golden, MD, MPH⁵, Navneet Hakhu, MS⁶, Katherine K. Thomas, BA⁷, James Hughes, PhD⁸, Nicole Jensen, MS⁹ and Patricia A. Totten, PhD¹⁰, 1Department of Epidemiology, University of Washington, Seattle, WA, 2Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, 3Public Health - Seattle & King County STD Clinic, Seattle, WA, 4University of Washington Center for AIDS & STD and Department of Epidemiology, University of Washington, Seattle, WA, 5Center for AIDS and STD, Public Health - Seattle & King County STD Clinic and Department of Medicine, University of Washington, Seattle, WA, 6UW Center for AIDS and STD, University of Washington, Seattle, WA, 7Center for AIDS & STD, University of Washington, Seattle, WA, 8Biostatitics, University of Washington, Seattle, WA, 9Center for AIDS and STD, University of Washington, Seattle, WA, 10Department of Medicine and Center for AIDS and STD, University of Washington, Seattle, WA

Background: Azithromycin (1g) or doxycycline (100mg bidx7d) are recommended for non-gonococcal urethritis (NGU). Recent evidence suggests azithromycin may be less effective than doxycycline.

Objectives: To assess the relative efficacy of azithromycin and doxycycline against NGU and associated pathogens.

Methods: : In a double-blind randomized trial, men with NGU (urethral symptoms or visible urethral discharge and ≥5 PMN/HPF) received a clinical exam and active azithromycin/placebo doxycycline or active doxycycline/placebo azithromycin at enrollment. Urine was tested for Chlamydia trachomatis (CT) and Trichomonas vaginalis (TV) by TMA (Gen-Probe, Inc.); for Mycoplasma genitalium (MG), and Ureaplasma urealyticum-biovar2 (UU-2) by PCR. At 3-week follow-up, clinical failure was defined as urethral symptoms or urethral discharge and ≥5 PMNs/HPF; microbiologic failure was defined as a positive test for CT, MG, or UU-2 among men initially infected with these pathogens.

Results: From January 2007-July 2010 we enrolled 532 men; 423 (80%) returned for follow-up. Mean age was 33.7 (±9.8), 54.1% were White, 34.0% were Black. Baseline prevalence was CT=26.5%, MG=14.4%, TV=2.1%, UU-2=27.1%, idiopathic=43.7%. Clinical cure was low and did not differ by arm (azithromycin=68.5%(148/216) vs doxycycline=66.0% (136/206), p=0.61), nor did it for CT:azithromycin=77.4% (41/53) vs doxycycline=64.0% (32/50), p=0.19; MG:azithromycin=50.0% (19/38) vs doxycycline=48.2% (13/27), p=1.0), UU-2:azithromycin=65.4% (32/52) vs doxycycline=69.1% (38/55), p=0.72; or idiopathic:azithromycin=71.7% (66/92) vs doxycycline=70.7% (58/92), p=1.0. Microbiologic cure also did not differ by arm for any pathogen (CT:azithromycin=86.3% (44/51) vs. doxycycline=90.0% (45/50), p=0.76; MG:azithromycin=39.5% (15/38) vs doxycycline=29.6% (8/27), p=0.44; UU-2:azithromycin=75.0% (39/52) vs. doxycycline=69.1% (38/55), p=0.53).

Conclusions: Clinical and microbiologic cure were low and there were no significant differences in efficacy of azithromycin versus doxycycline for either. Previous observations that azithromycin was less effective than doxycycline for CT and MG were not confirmed in this population.

Implications for Programs, Policy, and Research: Antimicrobial susceptibility likely varies regionally and should be routinely assessed. Development of new antibiotics should be prioritized.

LB.6 Low Cure Rates for Standard CDC Recommended Treatment for NGU: Results From a Double Blind Randomized Trial