Rather than just treating STIs with antibiotics, a new public health movement aims to prevent them in the first place with a type of antibiotic. Promising research on variations of this approach is promising, but it also raises concerns that it could contribute to another public health crisis: drug-resistant infections.
One thing is clear: the country desperately needs groundbreaking talent to combat the epidemic of sexually transmitted diseases such as gonorrhea, chlamydia and syphilis. Significantly increased Over the past 10 years.
Public health experts believed syphilis could potentially be eliminated until the 1990s, but the rise has been particularly worrying. Among pregnant women Congenital syphilis, in particular, can be fatal or cause severe birth defects if a mother passes it on to her baby.
Enter doxycycline, a common, well-tolerated antibiotic that has been used for many years for a variety of purposes, including treating acne.
Last month, the Centers for Disease Control and Prevention Published guidelines Doxycycline taken after sexual intercourse as post-exposure prophylaxis (doxyPEP) has been recommended to reduce the risk of bacterial sexually transmitted infections in gay and bisexual men and transgender women. This recommendation was limited to this population because a recent clinical trial of doxyPEP in gay and bisexual men and transgender women found that Cisgender No benefit was shown for women. Men who have sex with men also have disproportionately high rates of sexually transmitted diseases.
CDC approval three Randomized controlled trial Gay and bisexual men and transgender women prescribed doxycycline and instructed to take a single 200 milligram dose within 72 hours of sexual activity were found to reduce the risk of chlamydia and syphilis by more than 70 percent and gonorrhea by about 50 percent. Further studies of the use of doxyPEP in San Francisco’s gay community have similarly shown promising results.
“It’s too early to know whether doxy-PEP will reverse the long-standing increase in sexually transmitted diseases,” said Dr. Jonathan Mermin, CDC’s chief of sexually transmitted disease prevention, “but we are seeing considerable enthusiasm in the community and among many health care providers.”
Now, two new studies have broadened the debate about doxycycline and whether to use 100 mg of the antibiotic daily or 100 mg of doxycycline daily as pre-exposure prophylaxis.Pre-EP — For some people, it may provide a more optimal balance of risks and benefits.
Investigation result From these studiesThe results of the study, conducted among HIV-positive gay and bisexual men in Toronto, Canada, and Vancouver, British Columbia, and female sex workers in Tokyo, will be presented at the 25th International HIV Conference, being held in Munich, Germany, from July 22 to 26.
“Some patients prefer to add a pill to their daily medication routine and take it once a day without worrying about when or how they take it after sex,” Dr. Jeffrey Klausner, a professor of infectious diseases at the University of Southern California, said of the DoxiPrEP protocol. “Other patients prefer to take one pill after sex. It’s simple and easy.”
Klausner was not involved in the new study. First doxyPrEP studyA study of a small group of gay and bisexual men in Los Angeles, published in 2015, found that those in the doxyPrEP group were less likely to be diagnosed with an STI than those in the control group who were given financial incentives to avoid contracting an STI.
The main concern about prescribing doxycycline for prophylaxis is that it may encourage the emergence of drug-resistant infections such as staphylococcus aureus. Gonorrhea is the only one of the three STIs where such resistance has been documented. However, doxycycline To prevent In the case of gonorrhea, generally handle That infection.
On the other hand, by reducing the incidence of sexually transmitted diseases, doxycycline reduces the need to use other antibiotics to treat such infections, thereby reducing the likelihood that those drugs will cause drug resistance.
A new double-blind Canadian trial of DoxyPrEP enrolled 52 gay and bisexual men who were equally randomized to receive either doxycycline or a placebo. After one year, the doxyPrEP group had reduced the diagnosis rates of three STIs by 68% to 92%, respectively, a finding comparable to recent DoxyPEP studies.
Although the samples were very small, there was essentially no difference in drug resistance for staphylococcal infections between the two groups.
A Japanese study found that sexually transmitted disease infection rates fell by two-thirds among 40 women working in the sex industry. Rates fell from about 225 cases per 100 years of follow-up before doxycycline to 80 cases after. Syphilis disappeared when the women were prescribed daily doxycycline. Chlamydia fell by about two-thirds, but this change was only statistically significant. Gonorrhea did not change significantly.
The study authors found no change in signs of drug resistance in the two infections: bacterial vaginosis and candidal vaginosis.
About three-quarters of women reported reduced anxiety about contracting a sexually transmitted disease.
“It’s important to emphasize that these are both small studies,” Dr. Christoph Spinner, chief medical information officer at Liechts der Isar University Hospital in Munich and local co-chair of the upcoming HIV conference, said at a recent press conference. “Also, the Canadian study was a pilot study, and the Japanese study did not have a control group.”
A more enthusiastic Klausner reflected on the findings of the gay men study, saying they “compellingly support the idea that people should have choices when it comes to STI prevention tools. Current guidelines may need to be further updated.”
Dr. Troy Grennan, lead physician for the provincial HIV/STI program at the BC Centre for Disease Control in Vancouver and lead author of the gay men study, said the findings support a Canada-wide trial of doxyPEP versus doxyPrEP that his team began a year ago, with about 150 participants enrolled out of a planned 560.
“A general blanket statement that doxipep is better because it’s less drug is not the right conclusion to make,” he said.
First, for people who are fairly sexually active, it may make more sense to take doxycycline daily for PrEP, since it would actually require half the dose of doxycycline than doxyPEP, resulting in less overall use. Also, taking antibiotics continuously rather than intermittently may reduce the risk of emergence of drug resistance in pathogens.
Also, for people who already take medication daily, such as those for treating or preventing HIV, it may be easier to remember to take the medication every day than to base your dosing schedule on the timing of your most recent sexual activity.
As for concerns about promoting drug resistance, “the trends are not compelling in any case,” Glennan said. Research is underway to address the issue.
Like Klausner, Grennan emphasized the benefits of having STI prevention tools available to at-risk people.
“One size doesn’t fit all,” he said.
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