In a first, the US Centers for Disease Control and Prevention (CDC) has in a draft recommendation proposed for a powerful antibiotic pill for prevention of bacterial sexually transmitted infections (STI).

The CDC proposal called on doctors to consider prescribing post-exposure prophylaxis with doxycycline (doxycycline PEP) to help prevent the spread of STI infections like chlamydia, gonorrhoea, and syphilis infections.

The proposed guidelines, which applies only to men who have sex with men and transgender women, represents a new approach to addressing STI prevention in populations at increased risk for these infections.

“The purpose of the proposed guidelines is to provide updated clinical guidance for healthcare providers to inform the use of doxycycline PEP for preventing bacterial STI infections,” the CDC said in its draft recommendations.

“It’s going to take game-changing innovations for us to turn the STI epidemic around. And Doxy-PEP is the first major new prevention intervention we have for STIs in decades,” Jonathan Mermin, head of the CDC’s National Center for HIV, Viral Hepatitis, STD, and TB Prevention, said in an interview.

The CDC is seeking public comment on the proposal from interested persons and organisations now until November 16.

“We think this is the right step right now, even though science is still evolving,” he said.

The move comes as US continues to see an increase in cases of STIs caused by Neisseria gonorrhoeae (causative agent of gonorrhoea), Chlamydia trachomatis (causative agent of chlamydia), and Treponema pallidum (causative agent of syphilis).

Doxycycline, a broad-spectrum tetracycline antibiotic, is used as pre- or post-exposure prophylaxis to prevent infections such as malaria and Lyme disease.

It is well-absorbed and tolerated, with a half-life of approximately 12 hours. Doxycycline is the recommended treatment regimen for chlamydia and an alternative treatment for syphilis in non-pregnant patients with severe penicillin allergy or when penicillin is not available.

Meanwhile, the CDC is also planning multiple efforts to track real-world implementation of doxycyclinePEP, Mermin said, including monitoring for drug resistance.

“Given the gaps in science, long-term monitoring, evaluation and additional studies will be key for us to update the guidelines as needed. There are important questions that remain regarding potential risks,” said Mermin.