Is Using Antibiotics Before STI Exposure Risky
Jeffrey Klausner, MD, an infectious disease physician and professor of public health at the University of Southern California, is the first randomized trial of doxycycline (an antibiotic commonly used to treat infections such as syphilis and chlamydia). published a controlled study. 2015. Initially, the National Institutes of Health was unwilling to fund the study and expressed concern about possible antimicrobial resistance. At worst, the microbes change over time and become unresponsive to drugs, making treatment ineffective.
But as the STD crisis grows, health professionals are looking for new ways to help.
“Last year, there were more than 170,000 cases of syphilis [in the United States], and the annual number of cases has doubled for him in the last five years,” he says.
Repeated studies with slightly different designs also found lower rates of sexually transmitted infections in people who took doxycycline daily or after sex. was given.
And in October, the San Francisco Department of Public Health recommended doxyPEP for cisgender men and transgender women who have had a bacterial STI in the past year as well as condomless oral or anal sex with one or more cis men or trans women in the past year.
For those who meet the second criteria but haven't been diagnosed with an STI in the last year, the department is advising a ''shared decision-making approach,'' where doctors discuss the benefits and risks of doxyPEP and prescribe it for patients who feel they will benefit, explains Stephanie Cohen, MD, the department's acting director of disease prevention and control in the Population Health Division.
The department also recommends doxyPEP for anyone diagnosed with syphilis, regardless of their gender or sexual partners.
Cohen says the U.S. has among the highest rates of STIs in the world and that ''San Francisco, in particular, has some of the highest rates of sexually transmitted infections in the country.''
The most recent study of doxyPEP followed 501 men and trans women in Seattle and San Francisco. About two-thirds were taking HIV pre-exposure prophylaxis (HIV PrEP) and the rest were living with HIV. Sexually transmitted infections were lower in a group asked to take one dose of doxycycline within 72 hours of unprotected sex, according to the results of the study, presented at the International AIDS Society (IAS) conference earlier this year. understood. STI reduction was 66% in the HIV-PrEP group and 62% in the HIV-positive group.
''It can be a bit of a paradigm shift when you talk about using antibiotics before someone gets infected,'' says infectious disease doctor Annie Lütkemeyer, M.D. An STI researcher at the University of California, San Francisco, who co-led the study.
She recalls resistance after the advent of HIV PreP, which led to more risky sex and increased resistance to HIV drugs. In fact, she ''learned that access to HIV PrEP is absolutely essential for reducing HIV risk for some people.''
Well, the resistance to doxyPEP is that it could lead to more antimicrobial resistance. He points out that he is already exposed to high levels of antibiotics in order to
In the control group of this study, the incidence of sexually transmitted infections was 32% for her at 3 months, compared with 11% for her in the doxyPEP group. However, the use of doxyPEP was not perfect, with study participants reporting, on average, that they used it after her 87% of unprotected sex. ''It's not about taking doxycycline or not taking antibiotics,'' Lütkemeyer says. 50% higher exposure to ceftriaxone.
Still, Luetkemeyer and Klausner said it was important to monitor both drug-resistant STIs and other infections, such as doxycycline-resistant Staphylococcus aureus, to make sure DoxyPEP did not increase them. increase.
make things worse?
Luetkemeyer and her colleagues are currently investigating whether doxyPEP increases drug-resistant bacteria in recipients. No red flags yet, but research is ongoing.
The San Francisco Department of Health was the first to officially approve his doxyPEP, but doctors working with high-risk groups have been prescribing it off-label for years. Klausner said that when treating patients with HIV or at risk of HIV, he prescribed the prophylactic drug doxycycline daily or after sex without a condom, depending on how often the patient had sex. For emergency use, he usually started supplementing with his 15 doses of 200 milligrams.
He also points out that there are no certain groups that need doxyPEP, for example that people may benefit during periods between monogamous or relatively monogamous relationships. pointing out. ''People's risk profiles are dynamic. … doxyPEP is not a strategy that I encourage people to adopt forever,'' he says.
And while doxyPEP may increase the risk of drug-resistant infections, it could theoretically also reduce risk by reducing the population burden of sexually transmitted infections and the need for antibiotic treatment, he said. Klausner said.
“Since the 1970s, sexually transmitted diseases such as chlamydia, gonorrhea and syphilis have been known to be perpetuated by a core group of men who have had sex with many male partners for more than a month. he says. ''If we can control this spread in the core group, the rest of the population will be better protected.''
''When it comes to adoption, monitoring for worrisome signs of antimicrobial resistance is definitely a top priority,'' said Cohen of the San Francisco Public Health Department. Communities need new safeguards against sexually transmitted infections that outweigh the potential and unknown risks of antibiotic resistance. ''
What is certain is that decades of experience have shown that condoms, the only other means of prevention, are not acceptable to everyone because of their partners and personal preferences.
“We really need new tools because what we currently offer isn’t working in some populations where the incidence of sexually transmitted infections is so high,” he says.
15 Jan 2023