Clinical Research Directory

Inclusion Criteria: * Male, 16 to 45 years old. * Symptoms of non-gonococcal urethritis (NGU), including urethral discharge and/or dysuria for less than or equal to 14 days, or urethral discharge on exam. * Urethral smear with greater than or equal to 5 polymorphonuclear leukocytes (PMNs) per 3-5 oil immersion fields. * Willing to abstain from sexual intercourse or use condoms during the study. * Willingness to provide written consent. Exclusion Criteria: * Presence of gonorrhea at baseline visit. * History of recurrent non-gonococcal urethritis (NGU) (3 or more episodes in the prior year) or history of recent NGU (within past 30 days). * Signs or symptoms of epididymitis or prostatitis. * Known allergy to or intolerance of tinidazole, tetracyclines, macrolides or metronidazole. * History of photosensitivity related to doxycycline use. * Received systemic antibiotics within 30 days of study enrollment. * Unwillingness to abstain from alcohol for 24 hours after enrollment. * Serious underlying infection, including known HIV or other primary or secondary immunosuppression. * Concomitant infection, which requires antimicrobial therapy. * History of mental illness, which would preclude responsible participation in the study. * Current drug abuse that might affect ability to follow the protocol. * Previously enrolled in this study. * Men who have sex with men, due to different microbiology of NGU. * Voided within the previous hour. * Ingested alcohol within the past 8 hours. * Subject requires concurrent lithium, anticoagulation therapy, or antabuse.