UrethritisPhase 2NCT00322465
NGU: Doxycycline (Plus or Minus Tinidazole) Versus Azithromycin (Plus or Minus Tinidazole)
A Phase 2 study testing Doxycycline, Tinidazole and Azithromycin in people with Urethritis, run by National Institute of Allergy and Infectious Diseases (NIAID) at 4 sites in United States.
Trial summary
This study will look at the safety, effectiveness, and tolerability of combination medications for the initial treatment of non-gonococcal urethritis (NGU). NGU is inflammation of the tube that carries urine from the bladder. NGU is caused by bacteria that may be passed from person to person during sex. Read more about this study
- Who is it for?
- Ages 16 to 45 years, men only
- Conditions the study is for
- Urethritis
- What is being tested?
- Doxycycline, Tinidazole and Azithromycin
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 305 participants
- Where
- 4 sitesUnited States
- Study dates
- 17 Nov 2006to 20 Apr 2009
- Phase
- Phase 2
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 16 to 45 years
- Men only
- No healthy volunteers
- Child, Adult
Who may be able to join
- 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.
Who cannot join
- 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.
Show all 16Show fewer
- 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.
Trial locations and contacts
4 sites in 1 country.
United States4 sites
Johns Hopkins Hospital - Emergency Department
Baltimore, Maryland, 21287-0010
University of Alabama Hospital - Infectious Diseases
Birmingham, Alabama, 35249-0001
University of North Carolina School of Medicine - Center for Infectious Diseases
Chapel Hill, North Carolina, 27599-7030
Delgado Personal Health Center
New Orleans, Louisiana, 70112-3503
About this study
Official title: Phase II Randomized, Placebo-Controlled Double-Blind 4-Arm Trial for the Treatment of Non-Gonococcal Urethritis (NGU): Doxycycline (Plus or Minus Tinidazole) Versus Azithromycin (Plus or Minus Tinidazole)
This study will look at the safety, effectiveness, and tolerability of combination medications for the initial treatment of non-gonococcal urethritis (NGU). NGU is inflammation of the tube that carries urine from the bladder. NGU is caused by bacteria that may be passed from person to person during sex. This study will compare the 2 currently recommended NGU treatments, doxycycline and azithromycin, taken with tinidazole (another medication to treat certain sexually transmitted infections). Tinidazole used with doxycycline or azithromycin may cure NGU better than when doxycycline or azithromycin is used alone. Study participants will be 300 men ages 16-45 years with NGU attending sexually transmitted disease clinics in Birmingham, AL; New Orleans, LA; Durham, NC; and Baltimore, MD. Study participation will last 7 weeks and involve 3 visits. At each visit, participants will provide a urine sample, have 2 urethral swabs, and have their urethra checked for discharge indicating infection.
Read the detailed description
This study represents a clinical evaluation of the use of combination therapy for the initial treatment of non-gonococcal urethritis (NGU). This study will provide more current data on the comparison of cure rates between the 2 currently recommended therapies for NGU, doxycycline and azithromycin. Emerging clinical data has suggested that the latter may have become more efficacious for NGU as it is more effective in eradicating Mycoplasma (M.) genitalium from the genital tract than the former. Only in vitro data, limited as it is, suggests that doxycycline should be active against M. genitalium. The researchers hypothesize that cure rates for NGU will be significantly improved for both doxycycline and azithromycin using combination therapy with tinidazole. Important safety and tolerability data will be collected with regards to the use of combination therapy. Additionally, the study will provide data on the prevalence of the targeted pathogens in 4 geographic areas and on characteristics of men with NGU that may help to target populations who would benefit the most from combination therapy. The researchers hypothesize that currently recommended initial therapies for NGU are inadequate in at least certain populations due to lack of coverage for Trichomonas (T.) vaginalis. The researchers further hypothesize that between the 2 currently recommended regimens, azithromycin will result in a greater number of cures than doxycycline due to its greater efficacy in M. genitalium infected men. The primary study objectives are to: compare the clinical cure rates of doxycycline versus doxycycline with tinidazole; and azithromycin versus azithromycin with tinidazole for the treatment of NGU; and to evaluate the safety and tolerability of doxycycline/tinidazole and azithromycin/tinidazole in the treatment of NGU. Secondary study objectives are to: evaluate microbiological cure of Chlamydia (C.) trachomatis, T. vaginalis, M. genitalium in men treated with doxycycline versus doxycycline with tinidazole; and azithromycin versus azithromycin with tinidazole. Analysis will also include: (doxycycline plus doxycycline/tinidazole) versus (azithromycin plus azithromycin/tinidazole); for the clinical cure rates, analysis will also include: (doxycycline plus doxycycline/tinidazole) versus (azithromycin plus azithromycin/tinidazole); determine the prevalence of C. trachomatis, T. vaginalis, and M. genitalium in the study population of men with non-gonococcal urethritis; determine clinical, behavioral, and demographic predictors of the above organisms in men with non-gonococcal urethritis; and collect specimens for future studies to determine the role of unique and novel pathogens in the etiology of non-gonococcal urethritis. Outcome measures include clinical failure, clinical cure, microbiological cure, and unevaluable cure assessed at the first and second follow-up visits. Study participants will include 300 men ages 16-45 years with NGU attending sexually transmitted disease clinics in Birmingham, AL; New Orleans, LA; Durham, NC; and Baltimore, MD. Subjects will be randomly assigned to 1 of 4 active treatment arms: 75 subjects doxycycline; 75 subjects doxycycline plus tinidazole; 75 subjects azithromycin; and 75 subjects azithromycin plus tinidazole.
- Conditions
- Urethritis
- Being tested
- Doxycycline, Placebo, Tinidazole, Azithromycin
- Keywords
- azithromycin, doxycycline, non-gonococcal urethritis, sexually transmitted, tinidazole
- Medical subject headings
- Urethritis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
DoxycyclineDrug
100 mg orally, twice daily for 7 days.
PlaceboOther
Placebo capsule will be filled with lactose only and be identical in appearance to the capsule of Azithromycin, Tinidazole, Doxycycline.
TinidazoleDrug
2 gm single dose (4 tablets orally at 500 mg each).
AzithromycinDrug
1 gram (gm) (2 tablets orally at 500 milligrams (mg) each)
| Study group | Role | What they receive |
|---|---|---|
| Azithromycin | Experimental | Azithromycin 1 gram (gm) orally single dose (2 tablets at 500 milligrams (mg) each) plus doxycycline placebo twice daily for 7 days plus tinidazole placebo single dose. Receives: Other: Placebo; Drug: Azithromycin |
| Azithromycin + Tinidazole | Experimental | Azithromycin 1 gm orally single dose (2 tablets at 500 mg each) plus doxycycline placebo twice daily for 7 days plus tinidazole single dose (4 tablets at 500 mg each). Receives: Other: Placebo; Drug: Tinidazole; Drug: Azithromycin |
| Doxycycline | Experimental | Doxycycline 100 mg orally twice daily (2 pills/day = 200 mg/day) for 7 days plus placebo azithromycin orally single dose and placebo tinidazole. Receives: Drug: Doxycycline; Other: Placebo |
| Doxycycline + Tinidazole | Experimental | Doxycycline 100 mg orally twice daily for 7 days plus placebo azithromycin single dose plus tinidazole 2 gm orally single dose (4 tablets at 500 mg each). Receives: Drug: Doxycycline; Other: Placebo; Drug: Tinidazole |
What is being measured
The primary outcome is the main question the study is designed to answer.
Safety and Tolerability of Doxycycline/Tinidazole and Azithromycin/Tinidazole: Number of Participants Reporting Nausea
At all study visits, unsolicited adverse events were recorded. Nausea, Vomiting, Abdominal pain, and Diarrhea were recorded using National Cancer Institute Common Toxicity Criteria (Version 3.0).
Measured: First follow-up visit (Day 15-19), second follow-up visit (Day 35-45)
Safety and Tolerability of Doxycycline/Tinidazole and Azithromycin/Tinidazole: Number of Participants Reporting Vomiting
At all study visits, unsolicited adverse events were recorded. Nausea, Vomiting, Abdominal pain, and Diarrhea were recorded using National Cancer Institute Common Toxicity Criteria (Version 3.0).
Measured: First follow-up visit (Day 15-19), second follow-up visit (Day 35-45)
Safety and Tolerability of Doxycycline/Tinidazole and Azithromycin/Tinidazole: Number of Participants Reporting Stomach Upset
At all study visits, unsolicited adverse events were recorded.
Measured: First follow-up visit (Day 15-19), second follow-up visit (Day 35-45)
Safety and Tolerability of Doxycycline/Tinidazole and Azithromycin/Tinidazole: Number of Participants Reporting of Abdominal Pain
At all study visits, unsolicited adverse events were recorded. Nausea, Vomiting, Abdominal pain, and Diarrhea were recorded using National Cancer Institute Common Toxicity Criteria (Version 3.0).
Measured: First follow-up visit (Day 15-19), second follow-up visit (Day 35-45)
Safety and Tolerability of Doxycycline/Tinidazole and Azithromycin/Tinidazole: Number of Participants Reporting Diarrhea
At all study visits, unsolicited adverse events were recorded. Nausea, Vomiting, Abdominal pain, and Diarrhea were recorded using National Cancer Institute Common Toxicity Criteria (Version 3.0).
Measured: First follow-up visit (Day 15-19), second follow-up visit (Day 35-45)
Percentage of Participants Achieving Clinical Cure of Non-gonococcal Urethritis (NGU) With Doxycycline Versus Doxycycline With Tinidazole; and Azithromycin Versus Azithromycin With Tinidazole
Clinical Cure of NGU: Did not meet criteria for clinical failure at last evaluable follow-up visit.
Clinical Failure at first follow-up: [Persistent symptoms AND >= 5 polymorphonuclear leukocytes (PMNs) per 3-5 oil immersion fields (regardless of urethral discharge)] OR Persistent urethral discharge on exam (regardless of symptoms or number of PMNs).
Clinical Failure at second follow-up: >= 5 PMNs per 3-5 oil immersion fields (regardless of symptoms or presence of urethral discharge) OR Persistent urethral discharge on exam (regardless of symptoms or number of PMNs)
Measured: First follow-up visit (Day 15-19), second follow-up visit (Day 35-45)
Secondary outcomes (11)
Percentage of Participants Achieving Clinical Cure of NGU With (Doxycycline Plus Doxycycline/Tinidazole) Versus (Azithromycin Plus Azithromycin/Tinidazole)
Clinical Cure of NGU: Did not meet criteria for clinical failure at last evaluable follow-up visit.
Clinical Failure at first follow-up: [Persistent symptoms AND >= 5 PMNs per 3-5 oil immersion fields (regardless of urethral discharge)] OR Persistent urethral discharge on exam (regardless of symptoms or number of PMNs).
Clinical Failure at second follow-up: >= 5 PMNs per 3-5 oil immersion fields (regardless of symptoms or presence of urethral discharge) OR Persistent urethral discharge on exam (regardless of symptoms or number of PMNs)
Measured: First follow-up visit (Day 15-19), second follow-up visit (Day 35-45)
Percentage of Participants Achieving Microbiological Cure of Chlamydia Trachomatis With Doxycycline Versus Doxycycline With Tinidazole; and Azithromycin Versus Azithromycin With Tinidazole
Microbiological cure of Chlamydia trachomatis refers to the percentage of men with NGU who were negative for Chlamydia trachomatis at the last available result and had been positive for Chlamydia trachomatis at baseline.
Measured: First follow-up visit (Day 15-19), second follow-up visit (Day 35-45)
Percentage of Participants Achieving Microbiological Cure of Trichomonas Vaginalis With Doxycycline Versus Doxycycline With Tinidazole; and Azithromycin Versus Azithromycin With Tinidazole
Microbiological cure of Trichomonas vaginalis refers to the percentage of men with NGU who were negative for Trichomonas vaginalis (swab and urine specimens) at the last available result and had been positive for Trichomonas vaginalis at baseline (swab or urine specimen).
Measured: First follow-up visit (Day 15-19), second follow-up visit (Day 35-45)
Percentage of Participants Achieving Microbiological Cure of Mycoplasma Genitalium With Doxycycline Versus Doxycycline With Tinidazole; and Azithromycin Versus Azithromycin With Tinidazole
Microbiological Cure of Mycoplasma Genitalium refers to the percentage of men with NGU who were negative for Mycoplasma Genitalium at the last available result and had been positive for Mycoplasma Genitalium at baseline.
Measured: First follow-up visit (Day 15-19), second follow-up visit (Day 35-45)
Prevalence of Chlamydia Trachomatis in Men With Non-gonococcal Urethritis
Percentage of men with non-gonococcal urethritis that had a positive result for Chlamydia trachomatis at baseline (enrollment)
Measured: Baseline (enrollment visit)
Prevalence of Trichomonas Vaginalis (Swab or Urine Specimen) in Men With Non-gonococcal Urethritis
Percentage of men with non-gonococcal urethritis that had a positive result for Trichomonas vaginalis from a urethral swab or urine specimen at baseline (enrollment)
Measured: Baseline (enrollment visit)
Prevalence of Mycoplasma Genitalium in Men With Non-gonococcal Urethritis
Percentage of men with non-gonococcal urethritis that had a positive result for Mycoplasma genitalium at baseline (enrollment)
Measured: Baseline (enrollment)
Clinical, Behavioral, and Demographic Predictors of Chlamydia Trachomatis in Men With Non-gonococcal Urethritis
Clinical, behavioral, and demographic variables considered were discharge amount and appearance; condom use last sex; new recent partner; number of partners and new partners in last 30 days as well as last 3 months; number of times vaginal sex, oral sex, or anal sex in past 30 days; always/almost always used condom in last 3 months.
Measured: Baseline (enrollment visit)
Clinical, Behavioral, and Demographic Predictors of Trichomonas Vaginalis in Men With Non-gonococcal Urethritis
Trichomonas vaginalis was determined from urethral swab or urine specimen. Clinical, behavioral, and demographic predictors considered included discharge amount and appearance; condom use last sex; new recent partner; number of partners and new partners in last 30 days and last 3 months; number of times vaginal sex, oral sex, or anal sex in last 30 days; always/almost always used condom in last 3 months.
Measured: Baseline (enrollment visit)
Clinical, Behavioral, and Demographic Predictors of Mycoplasma Genitalium in Men With Non-gonococcal Urethritis
Logistic multiple regression with independent variable selection based on single variable models with p<0.10. Participants positive at enrollment for Mycoplasma genitalium from urine specimen. Potential variables: discharge amount and appearance; condom use last sex; new recent partner, number of partners and new partners in last 30 days and last 3 months; number of times vaginal sex, oral sex, or anal sex in last 30 days; always/almost always used condom last 3 months.
Measured: Baseline (enrollment visit)
Specimens for Future Studies to Determine the Role of Unique and Novel Pathogens in the Etiology of Non-gonococcal Urethritis
Urethral swabs and urine specimens collected at each study visit for future studies to determine the role of unique and novel pathogens in the etiology of non-gonococcal urethritis
Measured: Baseline (enrollment); First follow-up visit (Day 15-19), second follow-up visit (Day 35-45)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 May 2006 (estimated)
- Study start17 Nov 2006
- Primary completion20 Apr 2009
- Study completion20 Apr 2009
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for UrethritisStudies of the same condition, open and under way.
- More trials run by National Institute of Allergy and Infectious Diseases (NIAID)The sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 305 participants (actual)
Sponsor and investigators
- Sponsor type
- US National Institutes of Health
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00322465
- Sponsor's protocol ID
- 05-0120
- Status last verified
- 18 May 2011
- First submitted
- 4 May 2006
- Last updated
- 27 Aug 2026
- Results posted
- Yes, on ClinicalTrials.gov
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
Publications
Schwebke JR, Rompalo A, Taylor S, Sena AC, Martin DH, Lopez LM, Lensing S, Lee JY. Re-evaluating the treatment of nongonococcal urethritis: emphasizing emerging pathogens--a randomized clinical trial. Clin Infect Dis. 2011 Jan 15;52(2):163-70. doi: 10.1093/cid/ciq074.
PubMed 21288838
Study at a glance
From the registry record, last updated by the sponsor on 27 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Phase II Randomized, Placebo-Controlled Double-Blind 4-Arm Trial for the Treatment of Non-Gonococcal Urethritis (NGU): Doxycycline (Plus or Minus Tinidazole) Versus Azithromycin (Plus or Minus Tinidazole)
- ClinicalTrials.gov ID
- NCT00322465
- Acronym / sponsor ID
- 05-0120
- Conditions
- Urethritis
- Keywords
- azithromycin, doxycycline, non-gonococcal urethritis, sexually transmitted, tinidazole
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 305 participants (actual)
- Lead sponsor
- National Institute of Allergy and Infectious Diseases (NIAID)US National Institutes of Health
- Study start
- 17 Nov 2006 (actual)
- Primary completion
- 20 Apr 2009 (actual)
- Study completion
- 20 Apr 2009 (actual)
- First posted
- 8 May 2006 (estimated)
- Results
- Posted 17 Aug 2011
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study will look at the safety, effectiveness, and tolerability of combination medications for the initial treatment of non-gonococcal urethritis (NGU). NGU is inflammation of the tube that carries urine from the bladder. NGU is caused by bacteria that may be passed from person to person during sex. This study will compare the 2 currently recommended NGU treatments, doxycycline and azithromycin, taken with tinidazole (another medication to treat certain sexually transmitted infections). Tinidazole used with doxycycline or azithromycin may cure NGU better than when doxycycline or azithromycin is used alone. Study participants will be 300 men ages 16-45 years with NGU attending sexually transmitted disease clinics in Birmingham, AL; New Orleans, LA; Durham, NC; and Baltimore, MD. Study participation will last 7 weeks and involve 3 visits. At each visit, participants will provide a urine sample, have 2 urethral swabs, and have their urethra checked for discharge indicating infection.
Detailed description
This study represents a clinical evaluation of the use of combination therapy for the initial treatment of non-gonococcal urethritis (NGU). This study will provide more current data on the comparison of cure rates between the 2 currently recommended therapies for NGU, doxycycline and azithromycin. Emerging clinical data has suggested that the latter may have become more efficacious for NGU as it is more effective in eradicating Mycoplasma (M.) genitalium from the genital tract than the former. Only in vitro data, limited as it is, suggests that doxycycline should be active against M. genitalium. The researchers hypothesize that cure rates for NGU will be significantly improved for both doxycycline and azithromycin using combination therapy with tinidazole. Important safety and tolerability data will be collected with regards to the use of combination therapy. Additionally, the study will provide data on the prevalence of the targeted pathogens in 4 geographic areas and on characteristics of men with NGU that may help to target populations who would benefit the most from combination therapy. The researchers hypothesize that currently recommended initial therapies for NGU are inadequate in at least certain populations due to lack of coverage for Trichomonas (T.) vaginalis. The researchers further hypothesize that between the 2 currently recommended regimens, azithromycin will result in a greater number of cures than doxycycline due to its greater efficacy in M. genitalium infected men. The primary study objectives are to: compare the clinical cure rates of doxycycline versus doxycycline with tinidazole; and azithromycin versus azithromycin with tinidazole for the treatment of NGU; and to evaluate the safety and tolerability of doxycycline/tinidazole and azithromycin/tinidazole in the treatment of NGU. Secondary study objectives are to: evaluate microbiological cure of Chlamydia (C.) trachomatis, T. vaginalis, M. genitalium in men treated with doxycycline versus doxycycline with tinidazole; and azithromycin versus azithromycin with tinidazole. Analysis will also include: (doxycycline plus doxycycline/tinidazole) versus (azithromycin plus azithromycin/tinidazole); for the clinical cure rates, analysis will also include: (doxycycline plus doxycycline/tinidazole) versus (azithromycin plus azithromycin/tinidazole); determine the prevalence of C. trachomatis, T. vaginalis, and M. genitalium in the study population of men with non-gonococcal urethritis; determine clinical, behavioral, and demographic predictors of the above organisms in men with non-gonococcal urethritis; and collect specimens for future studies to determine the role of unique and novel pathogens in the etiology of non-gonococcal urethritis. Outcome measures include clinical failure, clinical cure, microbiological cure, and unevaluable cure assessed at the first and second follow-up visits. Study participants will include 300 men ages 16-45 years with NGU attending sexually transmitted disease clinics in Birmingham, AL; New Orleans, LA; Durham, NC; and Baltimore, MD. Subjects will be randomly assigned to 1 of 4 active treatment arms: 75 subjects doxycycline; 75 subjects doxycycline plus tinidazole; 75 subjects azithromycin; and 75 subjects azithromycin plus tinidazole.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, investigator)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Azithromycin | Experimental | Other: Placebo, Drug: AzithromycinAzithromycin 1 gram (gm) orally single dose (2 tablets at 500 milligrams (mg) each) plus doxycycline placebo twice daily for 7 days plus tinidazole placebo single dose. |
| Azithromycin + Tinidazole | Experimental | Other: Placebo, Drug: Tinidazole, Drug: AzithromycinAzithromycin 1 gm orally single dose (2 tablets at 500 mg each) plus doxycycline placebo twice daily for 7 days plus tinidazole single dose (4 tablets at 500 mg each). |
| Doxycycline | Experimental | Drug: Doxycycline, Other: PlaceboDoxycycline 100 mg orally twice daily (2 pills/day = 200 mg/day) for 7 days plus placebo azithromycin orally single dose and placebo tinidazole. |
| Doxycycline + Tinidazole | Experimental | Drug: Doxycycline, Other: Placebo, Drug: TinidazoleDoxycycline 100 mg orally twice daily for 7 days plus placebo azithromycin single dose plus tinidazole 2 gm orally single dose (4 tablets at 500 mg each). |
Who may qualify
- Ages
- 16 to 45 years
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult
Key inclusion criteria (5 listed)
- 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.
Key exclusion criteria (16 listed)
- 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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Doxycycline100 mg orally, twice daily for 7 days. | Drug | Doxycycline, Doxycycline + Tinidazole |
| PlaceboPlacebo capsule will be filled with lactose only and be identical in appearance to the capsule of Azithromycin, Tinidazole, Doxycycline. | Other | Azithromycin, Azithromycin + Tinidazole, Doxycycline, Doxycycline + Tinidazole |
| Tinidazole2 gm single dose (4 tablets orally at 500 mg each). | Drug | Azithromycin + Tinidazole, Doxycycline + Tinidazole |
| Azithromycin1 gram (gm) (2 tablets orally at 500 milligrams (mg) each) | Drug | Azithromycin, Azithromycin + Tinidazole |
Primary outcome
Safety and Tolerability of Doxycycline/Tinidazole and Azithromycin/Tinidazole: Number of Participants Reporting Nausea
Time frame: First follow-up visit (Day 15-19), second follow-up visit (Day 35-45)
At all study visits, unsolicited adverse events were recorded. Nausea, Vomiting, Abdominal pain, and Diarrhea were recorded using National Cancer Institute Common Toxicity Criteria (Version 3.0).
Safety and Tolerability of Doxycycline/Tinidazole and Azithromycin/Tinidazole: Number of Participants Reporting Vomiting
Time frame: First follow-up visit (Day 15-19), second follow-up visit (Day 35-45)
At all study visits, unsolicited adverse events were recorded. Nausea, Vomiting, Abdominal pain, and Diarrhea were recorded using National Cancer Institute Common Toxicity Criteria (Version 3.0).
Safety and Tolerability of Doxycycline/Tinidazole and Azithromycin/Tinidazole: Number of Participants Reporting Stomach Upset
Time frame: First follow-up visit (Day 15-19), second follow-up visit (Day 35-45)
At all study visits, unsolicited adverse events were recorded.
Safety and Tolerability of Doxycycline/Tinidazole and Azithromycin/Tinidazole: Number of Participants Reporting of Abdominal Pain
Time frame: First follow-up visit (Day 15-19), second follow-up visit (Day 35-45)
At all study visits, unsolicited adverse events were recorded. Nausea, Vomiting, Abdominal pain, and Diarrhea were recorded using National Cancer Institute Common Toxicity Criteria (Version 3.0).
Safety and Tolerability of Doxycycline/Tinidazole and Azithromycin/Tinidazole: Number of Participants Reporting Diarrhea
Time frame: First follow-up visit (Day 15-19), second follow-up visit (Day 35-45)
At all study visits, unsolicited adverse events were recorded. Nausea, Vomiting, Abdominal pain, and Diarrhea were recorded using National Cancer Institute Common Toxicity Criteria (Version 3.0).
Percentage of Participants Achieving Clinical Cure of Non-gonococcal Urethritis (NGU) With Doxycycline Versus Doxycycline With Tinidazole; and Azithromycin Versus Azithromycin With Tinidazole
Time frame: First follow-up visit (Day 15-19), second follow-up visit (Day 35-45)
Clinical Cure of NGU: Did not meet criteria for clinical failure at last evaluable follow-up visit. Clinical Failure at first follow-up: [Persistent symptoms AND >= 5 polymorphonuclear leukocytes (PMNs) per 3-5 oil immersion fields (regardless of urethral discharge)] OR Persistent urethral discharge on exam (regardless of symptoms or number of PMNs). Clinical Failure at second follow-up: >= 5 PMNs per 3-5 oil immersion fields (regardless of symptoms or presence of urethral discharge) OR Persistent urethral discharge on exam (regardless of symptoms or number of PMNs)
11 secondary outcomes
Percentage of Participants Achieving Clinical Cure of NGU With (Doxycycline Plus Doxycycline/Tinidazole) Versus (Azithromycin Plus Azithromycin/Tinidazole)
Time frame: First follow-up visit (Day 15-19), second follow-up visit (Day 35-45)
Percentage of Participants Achieving Microbiological Cure of Chlamydia Trachomatis With Doxycycline Versus Doxycycline With Tinidazole; and Azithromycin Versus Azithromycin With Tinidazole
Time frame: First follow-up visit (Day 15-19), second follow-up visit (Day 35-45)
Percentage of Participants Achieving Microbiological Cure of Trichomonas Vaginalis With Doxycycline Versus Doxycycline With Tinidazole; and Azithromycin Versus Azithromycin With Tinidazole
Time frame: First follow-up visit (Day 15-19), second follow-up visit (Day 35-45)
Percentage of Participants Achieving Microbiological Cure of Mycoplasma Genitalium With Doxycycline Versus Doxycycline With Tinidazole; and Azithromycin Versus Azithromycin With Tinidazole
Time frame: First follow-up visit (Day 15-19), second follow-up visit (Day 35-45)
Prevalence of Chlamydia Trachomatis in Men With Non-gonococcal Urethritis
Time frame: Baseline (enrollment visit)
Prevalence of Trichomonas Vaginalis (Swab or Urine Specimen) in Men With Non-gonococcal Urethritis
Time frame: Baseline (enrollment visit)
Prevalence of Mycoplasma Genitalium in Men With Non-gonococcal Urethritis
Time frame: Baseline (enrollment)
Clinical, Behavioral, and Demographic Predictors of Chlamydia Trachomatis in Men With Non-gonococcal Urethritis
Time frame: Baseline (enrollment visit)
Clinical, Behavioral, and Demographic Predictors of Trichomonas Vaginalis in Men With Non-gonococcal Urethritis
Time frame: Baseline (enrollment visit)
Clinical, Behavioral, and Demographic Predictors of Mycoplasma Genitalium in Men With Non-gonococcal Urethritis
Time frame: Baseline (enrollment visit)
Specimens for Future Studies to Determine the Role of Unique and Novel Pathogens in the Etiology of Non-gonococcal Urethritis
Time frame: Baseline (enrollment); First follow-up visit (Day 15-19), second follow-up visit (Day 35-45)
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 27 Aug 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Results publication: PubMed 21288838Schwebke JR, Rompalo A, Taylor S, Sena AC, Martin DH, Lopez LM, Lensing S, Lee JY. Re-evaluating the treatment of nongonococcal urethritis: emphasizing emerging pathogens--a randomized clinical trial. Clin Infect Dis. 2011 Jan 15;52(2):163-70. doi: 10.1093/cid/ciq074.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
4 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Doxycycline, Tinidazole and Azithromycin in people with Urethritis, run by National Institute of Allergy and Infectious Diseases (NIAID) at 4 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 16 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 27 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 4 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Yes. Results are posted in the registry (first posted 17 Aug 2011). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Safety and Tolerability of Doxycycline/Tinidazole and Azithromycin/Tinidazole: Number of Participants Reporting Nausea (time frame: First follow-up visit (Day 15-19), second follow-up visit (Day 35-45)). The study lists 6 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT00322465, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 27 Aug 2026.