Taking an antibiotic after sex helps gay men curb STDs — but might fuel drug resistance
A growing body of research shows taking doxycycline after sex helps prevent STDs, but some experts fear such intervention could fuel drug-resistant pathogens.
As the United States reckons with a burgeoning sexually transmitted disease crisis, a broadening chorus of public health experts are calling for the Centers for Disease Control and Prevention to endorse prescribing a preventive antibiotic pill to gay and bisexual men and transgender women at high risk of STDs.
But while a growing body of research shows that taking doxycycline after sex substantially lowers STD infection rates in this population — though not in cisgender women, according to the findings of a highly anticipated new study — some experts remain concerned that widespread use of the antibiotic for this purpose could do more harm than good by fueling the global crisis of antibiotic-resistant infections and harming people’s microbiomes.
“There’s going to be a very rigorous debate about whether this is a good idea, and for whom,” said Dr. Matthew Golden, director of the HIV and STD program in Seattle’s health department.
That debate has been at the forefront of the annual Conference on Retroviruses and Opportunistic Infections, which started Sunday in Seattle, with new findings from several studies of doxycycline for STD prevention unveiled Monday.
This includes the third randomized trial to find that instructing gay and bi men (one of the previous trials also included trans women) to take the antibiotic within 72 hours of sex without a condom — a protocol known as doxycycline post-exposure prophylaxis, or doxyPEP — lowers the risk of bacterial STDs. The new study, conducted in France, randomized about 500 gay and bi men to receive doxyPEP or no antibiotics and found doxycycline lowered the rates of gonorrhea, chlamydia and syphilis by 51% to 89%.
Another study found that in one of the other major doxyPEP trials, there was no marked increase in doxycycline resistance among three key bacteria, including gonorrhea and staph. However, this is not likely to resolve the ongoing debate on the matter.
Less controversial among public health experts is the potential for using a vaccine for STD prevention. The French study further found that a meningococcal B vaccine halved new gonorrhea infections.
The Seattle conference also saw findings from a randomized study of cisgender women in Kenya in which doxyPEP had no impact on their STD rates. Calling the study’s results “very disappointing,” its director, Dr. Jenell Stewart, an infectious disease physician at the University of Minnesota, said differences in anatomy, antibiotic resistance and adherence to the medication protocol could each at least partially explain the lack of efficacy in women while doxyPEP has consistently worked well in gay men in Western nations.
The new efficacy research shared Monday builds on previously released findings that in recent years have fueled increasing excitement within the infectious disease field over doxycyline’s promise as an answer to out-of-control STD transmission.
One study, conducted in Seattle and San Francisco and presented at a July conference, saw about a two-thirds overall reduction in STDs among gay and bi men and trans women. A previous French study, published in 2017, found the intervention dramatically cut syphilis and chlamydia infections, but did not affect gonorrhea.
“The data show in men a consistent benefit in terms of reducing the incidence of bacterial STIs,” Dr. Jean-Michel Molina, the lead author of both of the French studies and an LGBTQ health researcher at the Université Paris Cité, told NBC News, referring to the term sexually transmitted infections. He added that more research is needed to confirm the efficacy of the vaccine for gonorrhea.
Paul Marcelin, 48, a software engineer living in Alameda, California, participated in the Seattle-San Francisco study and was randomized into the control group that did not receive the antibiotic. After the study was discontinued early due to high efficacy, he was offered doxyPEP last summer. Read More…
