Q&A: What PCPs should know about CDC's new guidelines for doxy-PEP as STI prevention

Key takeaways:

• The CDC’s recent clinical guidelines recommend discussing doxy-PEP for STI prevention with certain populations.
• An expert described the conversations PCPs should be having with their patients.

At a time when sexually transmitted infections have been described as an epidemic, primary care providers should counsel specific patients on doxycycline for post-exposure prophylaxis, according to an expert.

The CDC recently published clinical guidelines that recommend counseling certain patients on doxycycline post-exposure prophylaxis (doxy-PEP) as a strategy to prevent bacterial STIs. Doxy-PEP has been proven to prevent bacterial STIs in men who have sex with men (MSM) and transgender women (TW) who are at risk for these infections, particularly chlamydia, gonorrhea and syphilis, according to the CDC.

In a joint press release, the Infectious Diseases Society of America and the HIV Medicine Association declared their support for the guidelines, as “doxy-PEP is the only biomedical intervention to prevent bacterial STIs and comes at a time when we urgently need new tools and approaches to control the STI epidemic.”

Healio spoke with Connie Celum, MD, MPH, a professor of global health, medicine and epidemiology, director of the International Clinical Research Center and director of the Center for AIDS Research at the University of Washington, to learn more about the new guidance and what it means for PCPs.

Healio: The CDC says clinicians should counsel MSM and TW about doxy-PEP. What should PCPs know about doxy-PEP, the evidence around it and the new recommendation?

Celum: Doxy-PEP has been shown in three clinical trials to reduce the risk for syphilis and chlamydia by 80% and gonorrhea by 33% to 50% among MSM and TW. It has similar efficacy among MSM and TW who are living with HIV and those who do not have HIV and are on pre-exposure prophylaxis (PrEP). The clinical trials enrolled MSM and TW who had syphilis, chlamydia and/or gonorrhea in the past year. People were counseled to take doxycycline (monohydrate or hyclate) 200 mg within 24 to 72 hours after condomless sex. They took an average of four doses per month. It was safe, well-tolerated and highly acceptable. One clinical trial of doxy-PEP was conducted among cisgender women in Kenya who were also taking tenofovir-based HIV PrEP and the results were flat; the main reason is thought to be due to low adherence based on only about 29% of the randomly selected women having doxycycline in hair samples. Another clinical trial is being designed to assess doxy-PEP among cisgender women in the U.S., which is a priority since women bear significant consequences including infertility, adverse pregnancy outcomes and ectopic pregnancy.

Healio: Why is this important? Can you discuss health equity in these populations?

Celum: We continued to see increases in bacterial STIs in the past decade, including very worrisome trends in all stages of syphilis and congenital syphilis. Doxy-PEP is the first new STI prevention intervention that has been identified for a long time and could substantially reduce STIs if those most at risk for STIs in the future are able to access it. Health equity is an important aspect of implementation that we have to pay attention to — those who could most benefit from doxy-PEP may have barriers to receiving it, either due to their access to health care, insurance or geography. We have seen persistent health inequities in HIV PrEP in terms of PrEP uptake being lowest in states and populations where HIV infection rates are the highest. It will be important to make sure that doxy-PEP is being used in populations and geographies with higher STI rates.

Healio: What are the steps PCPs need to be taking? What should this conversation with patients look like?

Celum: PCPs should be asking their patients about their sexual partners, condom use and if they have been tested for and/or diagnosed with STIs. It is helpful to try to make the discussion open-ended and “normative” (eg, ‘I ask all my patients about their sex lives because we are seeing sustained increases in STIs and have new tools to prevent STIs’).

Healio: Given the global increase in STIs , are there other, related discussions PCPs should have with their patients?

Celum: PCPs should be educating their patients about the ongoing high rates of STIs, asking about whether they can use condoms with some or all of their partners, encouraging STI testing and vaccines (HPV) based on age and mpox and meningococcal vaccination for MSM and TW.

Healio: What should providers do if a cisgender woman asks for — or seems like a good candidate — for doxy-PEP?

Celum: From the perspective of biology and pharmacokinetic data, doxy-PEP should work to reduce syphilis, chlamydia and gonorrhea in cisgender women. Recent pharmacokinetic data indicate similar doxycycline levels are achieved in plasma, rectal and vaginal secretions and tissue. At this point, while awaiting additional clinical trial data in cisgender women, a provider needs to consider doxy-PEP for cisgender women on a case-by-case basis (eg, a recent history of syphilis or other factors that may put her at higher risk).

Healio: What is the take-home message for PCPs here?

Celum: Doxy-PEP works well, especially against chlamydia and syphilis, and the goal is to make it available to those who could benefit the most. Providers should talk to their patients about their sex partners, whether they consider themselves at risk for STIs, STI testing, vaccines and doxy-PEP, particularly for MSM and TW with recent STIs or multiple partners.

References:

• CDC clinical guidelines on the use of doxycycline postexposure prophylaxis for bacterial sexually transmitted infection prevention, United States, 2024. https://www.cdc.gov/mmwr/volumes/73/rr/rr7302a1.htm. Published June 6, 2024. Accessed July 8, 2024.
• Doxy PEP as an STI prevention strategy. https://www.cdc.gov/sti/php/from-the-director/doxy-pep-sti-prevention-strategy.html. Accessed July 8, 2024.
• IDSA and HIVMA response to new CDC guidelines on doxycycline as post-exposure prophylaxis. https://www.idsociety.org/news--publications-new/articles/2024/idsa-and-hivma-response-to-new-cdc-guidelines--on-doxycycline-as-post-exposure-prophylaxis/. Published June 10, 2024. Accessed July 8, 2024.