Doxy-PEP: A New Opportunity to Reduce STIs

Doxy-PEP: A New Opportunity to Reduce STIs Posted By:

According to CDC data from 2022, more than 2.5 million cases of chlamydia, gonorrhea, and syphilis were reported in the United States. Over the past few years, we have seen a sharp increase in syphilis cases—a 17% increase from 2021 to 2022. Further, congenital syphilis cases dramatically increased by 31% over the same periods, respectively. This is layered on top of the national shortage of penicillin G benzathine, which is the preferred treatment for syphilis, which is expected to continue into summer 2024. Given these trends, there is a call to action for healthcare professionals (HCPs), health systems, and policy makers to address the ongoing public health issue of sexually transmitted infections (STIs).

Reducing STIs extends beyond the use of condoms. First and foremost, accurate and routine assessment of patients’ sexual practices is key to early detection and treatment. HCPs, including advanced practice providers, should incorporate routine screening based on clinical guidelines and better identify at-risk patients, which will then inform testing orders and treatment options for patients and their partners.

A New Opportunity
However, what about pharmacologic intervention in prevention? We have seen this strategy work well in HIV prevention. Currently, we have HIV pre-exposure prophylaxis (PrEP) and HIV post-exposure prophylaxis (PEP). In addition, we know that treating HIV to the point where it is undetectable in the blood eliminates the risk of transmission to others. This is referred to as “treatment as prevention” or “undetectable equals untransmittable (U=U)”. 

Therefore, could we adapt this successful model of care to address and prevent other STIs?

Doxy-PEP for Bacterial STIs
Doxycycline post-exposure prophylaxis (also referred to as doxy-PEP) is a strategy that has proven to reduce the combined incidence of chlamydia, gonorrhea, and syphilis among men who have sex with men and among transgender women—with or without HIV after condomless sex—by approximately 50% to more than 70%. Published studies detail the efficacy of this intervention. Unfortunately, a study examining doxy-PEP among cisgender women living in Kenya did not produce similar results. (Potential explanations for this phenomenon include low or suboptimal adherence, anatomy differences, and gonorrhea resistance.) Further, there are currently no studies looking at doxy-PEP efficacy among cisgender, heterosexual men.

Recognizing the potential impact of doxy-PEP in reducing rates of new STI infections, the CDC is drafting guideline recommendations. These guidelines were open for public comment in October 2023, and the final recommendations are pending at the time of this post.

The draft guidelines recommend 200 mg of oral doxycycline taken within 72 hours of condomless oral, anal, or vaginal sex for men who have sex with men and for transgender women with a history of one or more bacterial STI in the last year. Patients prescribed doxy-PEP should undergo routine screening (every 3-6 months) for bacterial STIs at anatomic sites of exposure. For those without HIV, routine screening for HIV infection should also be performed and HIV PrEP should be offered. Finally, all patients should be counseled about the potential side effects of doxycycline and risk of antimicrobial resistance. Ongoing data are being collected on antimicrobial resistance.

Many health departments across the US have already implemented local doxy-PEP protocols.  Although doxy-PEP may not be the needed magic bullet to eliminate STIs altogether, it may provide an opportunity to reduce incidence rates among targeted populations. Nurse practitioners and physician associates play a critical role in assessing and identifying candidates who may benefit from this intervention. More information on doxy-PEP and HIV PrEP/PEP can be found on the CDC guideline and CDC HIV Nexus websites.


Filed under: Nurses Week , Infectious Diseases , Urology , Preventive Medicine , Public Health , Substance Abuse , NPs & PAs