By Amy Norton 

HealthDay Reporter

THURSDAY, April 6, 2023 (HealthDay Information) — A “morning after” dose of a typical antibiotic can enormously decrease the possibilities of sexually transmitted bacterial infections in high-risk individuals, a brand new scientific trial has discovered.

Researchers found that taking the antibiotic doxycycline inside 72 hours of unprotected intercourse slashed the danger of gonorrhea, chlamydia and syphilis by two-thirds amongst homosexual and bisexual males and transgender girls who both had HIV or have been taking treatment to assist stop HIV.

The advantages on the one-year mark have been thought of so convincing that the trial was stopped early.

Consultants stated the findings, revealed April 6 within the New England Journal of Drugs, confirmed that the strategy to prevention is “extremely efficient.”

And that is wanted at a time when sexually transmitted infections (STIs) are rising at a “scary” charge, stated Dr. Colleen Kelley, an infectious illness specialist at Emory College in Atlanta, who was not concerned within the trial.

For the previous decade, america has seen a worrying comeback in bacterial STIs that had beforehand been on the decline. The pattern continued in 2020, a 12 months marked by pandemic restrictions: 2.4 million Individuals contracted chlamydia, gonorrhea or syphilis, in keeping with the U.S. Facilities for Illness Management and Prevention.

And whereas that sample cuts throughout demographics, males who’ve intercourse with different males have been disproportionately affected.

The brand new trial targeted on sure teams who’re at significantly excessive danger of bacterial STIs: Homosexual and bisexual males, in addition to transgender girls, who both had HIV or have been taking HIV PrEP (prescription treatment that helps stop HIV) and had been identified with a bacterial STI prior to now 12 months.

The researchers randomly assigned 500 members to one in every of two teams: About two-thirds got doxycycline and informed to take a 200 milligram dose inside 72 hours of unprotected intercourse; the remaining stayed with their regular well being care. All had STI testing achieved each three months.

Over one 12 months, members utilizing doxycycline have been two-thirds much less prone to be identified with a bacterial STI. In that group, the incidence of STIs each three months was round 11% — versus over 30% within the comparability group.

Preventive doxycycline was handiest towards chlamydia and syphilis — reducing the dangers of these infections by near 90% in HIV-negative individuals, and by nicely over 70% in these with HIV. The efficacy towards gonorrhea was much less, however these infections have been nonetheless reduce by 55%.

“It is thrilling to have one other software within the toolkit to forestall these infections,” stated lead researcher Dr. Annie Luetkemeyer, a professor of drugs on the College of California, San Francisco.

“We have tried counting on condom use,” she stated. “However enterprise as regular just isn’t working.”

That stated, Luetkemeyer pressured that any STI safety measure must be seen not as a magic bullet, however as “a part of a bundle” — which can embrace condom use, frequent STI screening and vaccination towards hepatitis B, as an example.

Luetkemeyer underscored one other level: The trial concerned particular teams at excessive danger of bacterial STIs, and nobody is saying that everybody ought to take doxycycline after having unprotected intercourse.

One concern is that wider use of the antibiotic might improve bacterial resistance to doxycycline and different antibiotics in its class.

However there has by no means been any documented resistance of syphilis or chlamydia to doxycycline, stated Kelley, who can also be vice chair of the HIV Drugs Affiliation’s board.

Some gonorrhea strains, nonetheless, are proof against the antibiotic. And Kelley stated it is doable that with time, morning-after doxycycline will change into much less efficient in stopping gonorrhea.

On the optimistic facet, each medical doctors stated, doxycycline just isn’t used to deal with gonorrhea, so any elevated resistance to the antibiotic shouldn’t hinder therapy of the STI.

One other query is how will common antibiotic use have an effect on an individual’s personal microbiome (the gathering of micro organism that naturally dwell within the physique). That can require extra analysis, Luetkemeyer stated.

However once more, each medical doctors stated, it is a matter of “steadiness.” For individuals at such excessive danger of bacterial STIs — who would usually be utilizing antibiotics to deal with them anyway — the advantages of preventive doxycycline might nicely outweigh the theoretical danger of altering the microbiome in a method that is dangerous, Kelley famous.

For the time being, doxycycline just isn’t routinely prescribed for STI prevention in high-risk people, Kelley stated — although some metropolis well being departments (like San Francisco) and suppliers have embraced it.

The U.S. Facilities for Illness Management and Prevention, she famous, is anticipated to quickly launch some steerage on the topic.

Luetkemeyer cautioned individuals towards utilizing doxycycline on their very own by shopping for it on-line or utilizing a pal’s prescription.

“It is at all times advisable to speak to a health care provider and ensure that is best for you,” she stated.

And for now, a minimum of, Luetkemeyer stated she wouldn’t advocate that cisgender girls use doxycycline for STI prevention, even when they’re at excessive danger.

This trial didn’t examine cisgender (organic) girls, however a latest trial in Kenya did and located that for younger girls utilizing HIV PrEP, morning-after doxycycline didn’t reduce the danger of bacterial STIs.

The explanations, Luetkemeyer stated, are unknown at this level.

Extra info

The U.S. Facilities for Illness Management and Prevention has extra on STD prevention.


SOURCES: Annie Luetkemeyer, MD, professor, drugs, College of California, San Francisco; Colleen Kelley, MD, MPH, affiliate professor, drugs, Emory College College of Drugs, Atlanta, vice-chair, board of administrators, HIV Drugs Affiliation, Arlington, Va.; New England Journal of Drugs, April 6, 2023

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