Study of Doxycycline to Prevent Sexually Transmitted Infections in Females Aged 13 to 29 in the U.S.

What this Trial Is About

This research aims to evaluate doxycycline as a preventive treatment to reduce bacterial sexually transmitted infections STIs such as gonorrhea, chlamydia, and early syphilis in adolescent and young adult females. The study also assesses how acceptable doxycycline use is and monitors antibiotic resistance, providing important information for public health decisions. The trial is open-label and randomized, enrolling females aged 13 to 29 years with recent STI exposure or infection. Participants are randomly assigned to one of three groups on-demand doxycycline post-exposure prophylaxis 200 mg taken shortly after condomless sex, weekly doxycycline 200 mg once a week regardless of sexual activity, or standard care involving quarterly STI testing and counseling. The study lasts one year with quarterly visits for testing and monitoring. Participants provide self-collected vaginal and rectal swabs, complete surveys, and use a smartphone app for weekly reporting of sexual activity and medication adherence. Resistance testing for doxycycline is also conducted on bacterial samples. Throughout the year, participants attend quarterly study visits for STI testing, safety checks, surveys, and sample collection. They use a mobile app to report weekly sexual activity and medication use to support adherence monitoring. Researchers measure combined rates of gonorrhea, chlamydia, and early syphilis infections as the primary outcome. Additional testing for antimicrobial resistance and participant acceptability of treatments is also conducted. The study involves close follow-up and safety monitoring over the full year.

Doxycycline Prophylaxis for Prevention of Sexually Transmitted Infections