Background:
Doxycycline postexposure prophylaxis (doxyPEP) is effective for preventing bacterial sexually transmitted infections (STIs) among people assigned male sex at birth. However, little is known about real-world use of antibiotics as STI prophylaxis, including prevalence and patterns of use, reasons for use, and potential user concerns.
Methods:
We conducted a national online survey in September 2023, with participants recruited via sexual networking apps used mainly by gay and bisexual men (GBM). Survey domains included sociodemographics, use of antibiotics as STI prophylaxis (including but not limited to doxyPEP), HIV/STI diagnosis history, HIV PrEP use, and sexual behavior. We used chi-square tests to compare characteristics of STI prophylaxis users and non-users.
Results:
As of 27 September 2023, 649 respondents in 50 states, DC, and Puerto Rico had completed the survey. Most (89%) were GBM, and 42% were HIV PrEP users, 19% living with HIV, 59% White, 23% Black, and 13% Latinx. Overall, 95% were interested in using STI prophylaxis; 49% had previously heard of it, and 22% and 16% had used it ever or in the past 12m, respectively. Of the 143 respondents with any STI prophylaxis use, 45% had used it before sex and 72% after sex; of those who used it after sex, 45% had taken it within 24h. Those with STI prophylaxis use in the past 12m used it for some (47%), most (32%), or all (21%) sex acts with casual partners. Medications used as STI prophylaxis included doxycycline (78%), amoxicillin (19%), and azithromycin (16%), and medication sources included leftover from treatment of a past STI (11%) or other condition (20%) and bought online without a prescription (12%). Compared to non-users, STI prophylaxis users were younger (mean age 39 vs 43, P=0.007) and a higher proportion were HIV PrEP users (56% vs 38%, P<0.001), reported >10 partners (61% vs 31%, P<0.001) or group sex (74% vs 49%, P<0.001) in the past 12m, and ever had an STI (75% vs 47%, P<0.001). Reasons for interest/use and concerns about use varied (Figure). For doxyPEP specifically, 36% had heard of it and 13% had used it in the past 12m, of whom 24% had used a dosage other than the 200mg dose shown to be effective.
Conclusions:
Interest in STI prophylaxis is nearly universal and use is already common among GBM engaged in online networks. Some are using medications and dosing that are untested as STI prophylaxis. Findings can inform doxyPEP implementation strategies, including education on effective dosing and monitoring of actual use.
