What is the relationship between Doxycycline (Doxy) and Peptic Ulcer Disease (pep)?

From the Guidelines

Doxycycline post-exposure prophylaxis (Doxy PEP) is recommended for men who have sex with men and transgender women who have had recent STIs and engage in high-risk sexual behavior, with a regimen of 200mg taken as a single oral dose within 72 hours after condomless sexual contact, as supported by the CDC clinical guidelines 1. The recommended approach is most beneficial for reducing the risk of contracting bacterial STIs including chlamydia, syphilis, and some strains of gonorrhea by approximately 65-80% 1. Key points to consider when using Doxy PEP include:

• Taking the medication with a full glass of water, either with or without food, though taking it with food may reduce stomach upset 1
• Common side effects include nausea, sun sensitivity, and yeast infections 1
• Doxy PEP works by inhibiting bacterial protein synthesis, preventing bacteria from multiplying in the body after exposure 1
• It should be used alongside other prevention strategies like condoms and regular STI testing, not as a replacement for them 1
• Counseling on the benefits and potential harms of doxycycline PEP, including known side effects and the potential for the development of antimicrobial resistance, is essential 1
• Guidance on actions to take to mitigate potential side effects, such as taking doxycycline on a full stomach and avoiding lying down for 1 hour after taking the medication, should be provided 1.

From the FDA Drug Label

Patients taking doxycycline for malaria prophylaxis should be advised: that no present-day antimalarial agent, including doxycycline, guarantees protection against malaria. to avoid being bitten by mosquitoes by using personal protective measures that help avoid contact with mosquitoes, especially from dusk to dawn that doxycycline prophylaxis: should begin 1 to 2 days before travel to the malarious area, should be continued daily while in the malarious area and after leaving the malarious area, should be continued for 4 further weeks to avoid development of malaria after returning from an endemic area, should not exceed 4 months

The use of doxycycline as a prophylactic measure against malaria is supported by the FDA drug label.

• The patient should start taking doxycycline 1 to 2 days before traveling to a malarious area.
• The patient should continue taking doxycycline daily while in the malarious area and after leaving the area for 4 weeks.
• Doxycycline prophylaxis should not exceed 4 months 2

From the Research

Doxy PEP Efficacy

• Doxycycline post-exposure prophylaxis (doxyPEP) has been shown to reduce the incidence of bacterial sexually transmitted infections (STIs) in men who have sex with men (MSM) and transgender women 3, 4.
• A study published in the New England Journal of Medicine found that doxyPEP reduced the incidence of STIs by two-thirds compared to standard care 4.
• Another study published in Clinical Infectious Diseases found that prescribing doxyPEP to all individuals would have averted 71% of STI diagnoses, while prescribing to PrEP users/PWH would have averted 60% of STI diagnoses 3.

Doxy PEP Prescribing Strategies

• Prescribing doxyPEP to individuals with STIs, particularly concurrent or repeated STIs, could avert a substantial proportion of all STI diagnoses 3.
• The most efficient prescribing strategies are based on STI history rather than HIV status or PrEP use 3.
• A study published in Current HIV/AIDS Reports highlighted the need for further research on the efficacy of doxyPEP for Neisseria gonorrhoeae infection and among cisgender women 5.

Population-Level Impact

• A population-level interrupted time series analysis found that the release of citywide doxyPEP guidelines in San Francisco was associated with decreases in reported cases of chlamydia and early syphilis, but not gonorrhea, among MSM and transgender women 6.
• The study suggested that supporting doxyPEP implementation for MSM and transgender women at risk for STIs could have a significant impact on the nationwide STI epidemic 6.

Safety and Adverse Effects

• A study published in the New England Journal of Medicine found that doxyPEP was well-tolerated, with only five grade 3 adverse events and no serious adverse events attributed to doxycycline 4.
• However, there are concerns about the potential for antimicrobial resistance and alterations to the gut microbiome with widespread use of doxyPEP 5.