Doxycycline Prophylaxis for Prevention of Sexually Transmitted Infections
Doxycycline Prophylaxis for Prevention of Sexually Transmitted Infections Among Adolescent and Young Adult Females in the United States
Westat
760 participants
Feb 27, 2026
INTERVENTIONAL
Conditions
Summary
The goal of this open-label, randomized trial is to assess the efficacy of doxycycline prophylaxis in reducing incidences of bacterial sexually transmitted infections (STIs) among adolescent and young adult females while also evaluating acceptability and antimicrobial resistance in order to inform public health policy.
Eligibility
Inclusion Criteria7
- Age 13-29 years, inclusive;
- Self-reports GC, CT, and/or early syphilis diagnosis in the 12 months prior to screening;
- Self-reports condomless (oral, vaginal, and/or anal) intercourse at least once in the 30 days prior to screening
- Is at least 45 kilograms (99.2 pounds) in weight
- Fluent in English (able to read, speak, and understand English);
- Willing to undergo all required study procedures; and
- Willing to provide written informed consent to participate in the study.
Exclusion Criteria9
- Is male;
- Is pregnant, breastfeeding, or planning to become pregnant in the next 12 months;
- Documented history of tetracycline allergy or self-reports an allergy to tetracyclines;
- Current or anticipated use of a medication (e.g., barbiturates, phenytoin, lithium, carbamazepine, systemic retinoids, warfarin) with a contraindicated interaction to doxycycline ;
- Current or planned use of doxycycline for a prolonged period (> 2 weeks) in the 30 days prior to enrollment, including current prescription for doxycycline for STI prophylaxis;
- Prolonged antibiotic use (> 2 weeks) within the last 30 days prior to enrollment;
- Co-enrollment in any other concurrent interventional research or studies that may interfere with this study, such as an STI prevention trial, unless approved by Protocol Team in writing;
- Does not have consistent access (or anticipated weekly access for 52 weeks of survey completion) to smartphone that can access the HMP app; or
- Any other medical condition, medical/behavioral intervention, or other conditions that, in the opinion of the clinical site Project Lead (PL)/Investigator of Record (IoR) or designee, could interfere with adherence to study procedures or compromise interpretation of study results.
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Interventions
200 mg of doxycycline taken by mouth as soon as possible and within 72 hours after any condomless oral, vaginal, and/or anal sex along with STI screening and sexual health counseling
200 mg of doxycycline taken by mouth weekly regardless of sexual activity along with STI screening and sexual health counseling
Quarterly STI testing/treatment and sexual health counseling
Locations(13)
View Full Details on ClinicalTrials.gov
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NCT06738407