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Search / Trial NCT05840159

A Study of Doxycycline to Treat Chlamydial Infection

Launched by NATIONAL INSTITUTE OF ALLERGY AND INFECTIOUS DISEASES (NIAID) · Apr 21, 2023

Trial Information

Current as of August 11, 2025

Recruiting

Keywords

Chlamydia Doxycycline Infection Intervention Phase 4

ClinConnect Summary

This clinical trial is studying the effectiveness of two different treatment plans using doxycycline to cure chlamydial infections. The trial is open to individuals of any gender identity who are 16 years or older and have been diagnosed with untreated chlamydia—those assigned female at birth with urogenital chlamydia and those assigned male at birth with rectal chlamydia. Participants will be randomly assigned to receive either a 3-day or a 7-day course of doxycycline.

During the trial, participants will receive medications in identical packages to maintain the study's blind, meaning neither the participants nor the researchers will know which treatment each participant is receiving. After 28 days, participants will return to the clinic for a follow-up test to see if the infection has been cleared. It's important for participants to be willing to abstain from certain sexual activities during the study and to keep all follow-up appointments. This trial aims to find out if a shorter course of doxycycline is just as effective as the longer one, which could help in treating chlamydia more efficiently.

Gender

ALL

Eligibility criteria

  • Inclusion Criteria:
  • 1. Has untreated urogenital chlamydia (CT) (in women) or rectal CT (in men), diagnosed with a positive nucleic acid amplification test (NAAT) (point-of care or laboratory-based)\* result within 14 days
  • \*Point-of-care (POC) test may or may not be FDA-cleared for CLIA waiver for diagnosis depending upon anatomic site of infection.
  • 2. Must be age \>/=16 years (where the IRB permits individuals aged 16-17 years old to consent to research); otherwise age \>/= 18 years
  • 3. Willing and able to understand and provide written informed consent before initiation of any study procedures
  • 4. Willing to complete a 7-day study drug regimen
  • 5. Willing to abstain from condomless anal or vaginal sex during the trial
  • 6. Willing and able to adhere to planned study procedures for all study visits
  • 7. Has valid contact information
  • Exclusion Criteria:
  • 1. For women: lower abdominal or pelvic pain or other signs or symptoms consistent with a clinical diagnosis of pelvic inflammatory disease (PID) Per the CDC's 2021 STD Treatment Guidelines or refer to local guidelines.
  • 2. Signs and symptoms that, in the judgement of a qualified clinician, warrant a prolonged course of treatment with doxycycline For example, 21 days of doxycycline for presumed lymphogranuloma venereum infection.
  • 3. Received antimicrobial therapy active against C. trachomatis within 21 days prior to positive chlamydia (CT) test result, or between the positive chlamydia (CT) test result and study enrollment Use of the following antibiotics is exclusionary: doxycycline and related tetra- or glycylcyclines, macrolides (including azithromycin), fluoroquinolones, rifampin, quinupristin-dalfopristin, and linezolid. Note: Amoxicillin, penicillin, ceftriaxone, and other beta-lactam antibiotics are not considered exclusionary for this study.
  • 4. Planning to take antimicrobial therapy active against chlamydia (CT) during the study period (e.g. doxycycline post-exposure prophylaxis, treatment for Mycoplasma genitalium infection, acne, or any other non-STI medical condition).
  • 5. Currently enrolled in or plan to enroll in another study using antimicrobial therapy active against C. trachomatis during the study period
  • 6. Pregnant or lactating, or plan to become pregnant within the study period
  • 7. Known moderate to severe allergy to tetracyclines, excluding tetracycline-induced photosensitivity.
  • 8. Plan to move or travel to another location that would preclude study follow-up appointments in clinic in the next 30 days
  • 9. Use of a medication contraindicated to treatment with doxycycline within 7 days prior to enrollment or during the study period (systemic retinoids, barbiturates, carbamazepine, phenytoin, warfarin)
  • 10. Previous enrollment in this trial
  • 11. Any condition that, in the judgment of the investigator, precludes participation because it could affect participant safety or determination of study endpoints.
  • Of note, the following factors will NOT exclude participants from the study:
  • Concomitant untreated gonorrhea (rectal, pharyngeal, or urethral) or known exposure to gonorrhea in the time between CT testing and study enrollment. Gonococcus (GC) infection identified during the course of pre-screening or screening will be treated per clinic standard practice and in accordance with local guidelines without concomitant azithromycin or other treatment for Chlamydia trachomatis infection.
  • Clinical diagnosis of concomitant untreated primary or secondary syphilis or known exposure to syphilis
  • Urethritis among men
  • Contraception status
  • Diagnosis of HIV

About National Institute Of Allergy And Infectious Diseases (Niaid)

The National Institute of Allergy and Infectious Diseases (NIAID) is a key component of the National Institutes of Health (NIH) dedicated to advancing the understanding, prevention, and treatment of infectious and immune-mediated diseases. Through rigorous clinical trials, NIAID aims to foster innovative research that enhances public health and addresses global health challenges, including emerging infectious diseases and allergies. The institute collaborates with various partners, including academic institutions, industry, and international organizations, to translate scientific discoveries into effective therapies and vaccines. NIAID's commitment to high-quality clinical research is integral to improving health outcomes and informing policy decisions in the realm of infectious diseases and immunology.

Locations

Seattle, Washington, United States

Rochester, New York, United States

Atlanta, Georgia, United States

Atlanta, Georgia, United States

Rochester, New York, United States

Atlanta, Georgia, United States

Thika, , Kenya

Atlanta, Georgia, United States

Seattle, Washington, United States

Mombasa, , Kenya

Mombasa, , Kenya

Thika, , Kenya

Birmingham, Alabama, United States

Patients applied

BG

CM

JC

3 patients applied

Timeline

First submit

Trial launched

Trial updated

Estimated completion

Not reported