Published on
Updated
Reading 3 mins.
According to a study conducted by scientists in the United States, taking an oral antibiotic (doxycycline) reduced the risk of sexually transmitted infections by two thirds. On one specific condition: that the treatment be taken within 72 hours of having sex without a condom.
Apart from the condom, the possibilities of reducing the risk of transmission of sexually transmitted infections are reduced (apart from the Prep which only has an effect on the prevention of HIV infection). But a new study using a broad-spectrum antibiotic could complete this therapeutic arsenal.
Study on individuals at high risk of STIs
Because they are at higher risk of contracting sexually transmitted infections, the study focused on men who have sex with men. Researchers from the University of California, San Francisco and the University of Washington, Seattle recruited 501 adults aged 18 and over at four clinics in the two cities.
These individuals, assigned male at birth, reported having had sex with a male in the previous year. They have also either been diagnosed with HIV or taking (or planning to take) pre-exposure prophylaxis (PrEP) medications to prevent HIV acquisition. To be specific, among those enrolled, 327 participants were taking PrEP drugs for HIV and 174 participants were people living with HIV.
Finally, these people had been diagnosed with gonorrhea, chlamydia or syphilis during the previous year.
Comparing standard care to taking unprotected post-intercourse doxycycline
The participants were randomly divided into two groups, one receiving doxy-PEP, the other following the standard care protocol. Doxycycline or doxy-PEP is a broad-spectrum antibiotic from the tetracycline family.
Those in the doxy-PEP group were instructed to take a 200-milligram doxycycline delayed-release tablet, ideally within 24 hours but no later than 72 hours after sex without a condom.
Thereafter, participants were assessed by study scientists every three months to assess compliance and side effects of drug treatment. They were also tested for STIs. Participants’ tolerance of the drug was assessed during clinical visits at 6 and 12 months. An independent data and safety monitoring committee reviewed study progress and safety and efficacy data every six months.
Fewer STIs when taking the antibiotic
The comparison between the two groups during quarterly visits to the clinic shows that:
- Among participants on PrEP for HIV, at least one or more STIs were diagnosed in 10.7% of men in the doxy-PEP study group. This figure is 31.9% in the group receiving standard care;
- Among study participants living with HIV, one or more STIs were diagnosed in 11.8% of men in the doxy-PEP group versus 30.5% in the standard care group;
- Participants reported good medication adherence, with 86.2% reporting taking doxy-PEP regularly within 72 hours of condomless sex, and 71.3% reporting never missing a dose. Additionally, no safety or acceptability issues were identified in the study.
Specifically, the post-exposure approach resulted in a two-thirds reduction in the incidence of syphilis, gonorrhea, and chlamydia among study participants, all of whom reported having had an STI during their lifetime. the previous year. However, research has also revealed a slight increase in antibacterial resistance. A data that requires more research, according to the authors.
Beware of possible antibiotic resistance
Gonorrhea was the most frequently diagnosed STI in the study. By examining the potential for antimicrobial resistance when using doxy-PEP, researchers found tetracycline resistance in more incident gonorrhea strains among those in the doxy-PEP group than among those in the doxy-PEP group. standard care (38.5% versus 12.5%, respectively).
“Given its demonstrated efficacy in multiple trials, doxy-PEP should be considered as part of a package of care for men who have sex with men and gender trans people if they are at increased risk for STIssays Dr. Annie Luetkemeyer, professor of infectious diseases at UCSF’s Zuckerberg San Francisco General Hospital and co-principal investigator of the study.
“It is now important to monitor the impact of doxy-PEP on antibiotic resistance patterns over time and compare this to the demonstrated benefits of reducing STIs. ” she concludes.