Can a second drug boost the cure rate for a common sexually transmitted infection?
NCT ID NCT00322465
First seen Aug 27, 2026 · Last updated Aug 28, 2026 · Updated 1 time
Summary
This trial tests whether adding tinidazole to the standard antibiotics doxycycline or azithromycin cures non-gonococcal urethritis (NGU) better than antibiotics alone. NGU is a bacterial infection causing inflammation of the urethra, often passed through sex. About 300 men aged 16 to 45 with NGU will receive one of four treatments: doxycycline, doxycycline plus tinidazole, azithromycin, or azithromycin plus tinidazole. Researchers will compare cure rates and track side effects like nausea and stomach upset over a 7-week period.
What this could mean
Our plain-language read of the trial. This is informational only, not medical advice or a prediction.
- Active substance
- Doxycycline, azithromycin, and tinidazole (antibiotics and an antiparasitic drug)
- What this could lead to
- If adding tinidazole improves cure rates, it could lead to a more effective first-line treatment for non-gonococcal urethritis, reducing persistent infections.
- What could go wrong
- This is a Phase 2 trial, so results are preliminary. The added drug may not improve outcomes and could increase side effects like nausea or stomach upset.
This is an AI summary of the original study and may miss details. Read our disclaimer.
Study facts
What this study's own registry entry says, in plain language.
- Phase
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Phase 2
Tests whether the treatment actually works, and watches for side effects, in a larger group.
- Participants
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305 people
The number who actually took part.
- Started
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Nov 2006
- Finished
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Apr 2009
- Lead sponsor
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A government research agency
The lead sponsor is the US National Institutes of Health.
Who can take part
This study's own entry requirements. Only the study team can say for certain whether you qualify.
- Ages
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16 to 45 years
- Sex
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Male participants only
- Healthy volunteers
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Not accepted
This study is not open to healthy volunteers. The entry requirements below say who it is open to.
Show the full entry requirements Hide the full entry requirements
Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.
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.
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Conditions
The condition(s) this trial relates to.
As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
Contacts and locations
Locations
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Delgado Personal Health Center
New Orleans, Louisiana, 70112-3503, United States
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Johns Hopkins Hospital - Emergency Department
Baltimore, Maryland, 21287-0010, United States
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University of Alabama Hospital - Infectious Diseases
Birmingham, Alabama, 35249-0001, United States
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University of North Carolina School of Medicine - Center for Infectious Diseases
Chapel Hill, North Carolina, 27599-7030, United States
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