Use of Doxycycline and Other Antibiotics as Bacterial Sexually Transmitted Infection Prophylaxis in a US Sample of Primarily Gay and Bisexual Men.

Abstract

Background: Doxycycline used as postexposure prophylaxis (doxyPEP) within 72 hours of sex reduces the risk of bacterial sexually transmitted infections (STIs) in people assigned male sex at birth. Little is known about current use of antibiotics as STI prophylaxis in US populations likely to benefit from doxyPEP.

Methods: We conducted an online survey in September 2023 of US adults recruited via sexual networking apps used mainly by gay and bisexual men (GBM). Respondents were asked about the use of antibiotics around the time of sex to prevent bacterial STIs.

Results: Of 903 respondents, most (96.2%) identified as GBM; 19.0% were living with HIV and 42.5% were using HIV preexposure prophylaxis (PrEP). Half (49.1%) had heard of using antibiotics to prevent STIs, and 95.6% were interested in use. Overall, 21.0% had used antibiotic STI prophylaxis, and 15.9% had done so in the past year. Among those reporting any use, most (78.1%) had used doxycycline; some used amoxicillin (16.7%), azithromycin (14.5%), or other antibiotics (14.1%). Among those reporting use in the past year, 46.9% used it for some, 28.1% for most, and 25.0% for all sex acts with casual partners during that period. Most (78.3%) of STI prophylaxis users reported their condom use did not change during periods of STI prophylaxis use, 17.2% indicated their condom use declined, and 4.5% indicated their condom use increased. For doxyPEP specifically, 35.7% had heard of it, and 13.0% had used it in the past year, of whom 21.0% had used a dosage other than the 200-mg dose shown to be effective.

Conclusions: In this sample of primarily GBM, interest in bacterial STI prophylaxis was nearly universal. However, some of the use was not informed by current clinical guidance or evidence from research studies. Efforts are needed to increase awareness of effective dosing and monitor real-world use.