From the Guidelines
The recommended dose of doxycycline for Post-Exposure Prophylaxis (PEP) is 200 mg taken as a single oral dose within 72 hours after potential exposure to certain sexually transmitted infections (STIs). This regimen is specifically intended to prevent bacterial STIs such as chlamydia, syphilis, and gonorrhea (though resistance to doxycycline exists for some gonorrhea strains) 1. The medication should be taken with a full glass of water, and can be taken with or without food, though taking it with food may reduce stomach upset.
Key Considerations
- Doxycycline PEP is not effective against HIV, hepatitis, or viral STIs.
- Doxycycline PEP is most appropriate for individuals at high risk of bacterial STIs and should be discussed with a healthcare provider, as it is not universally recommended due to concerns about antibiotic resistance and side effects 1.
- Common side effects may include nausea, photosensitivity (increased sun sensitivity), and yeast infections.
- Doxycycline should be avoided in pregnancy and in children under 8 years old due to potential effects on bone development and tooth discoloration.
Administration and Counseling
- The medication should be taken exactly as individually prescribed and only for its intended purpose.
- Patients should not take more than 200 mg of doxycycline per 24 hours; doses should be taken as soon after sex as possible, but no later than 72 hours 1.
- Counseling should include a discussion of the benefits and potential harms of doxycycline PEP, including known side effects and the potential for the development of antimicrobial resistance in other pathogens and commensal organisms 1.
From the FDA Drug Label
ADULTS: 100 mg of doxycycline, by mouth, twice a day for 60 days. CHILDREN: weighing less than 100 lb (45 kg); 1 mg/lb (2.2 mg/kg) of body weight, by mouth, twice a day for 60 days. Children weighing 100 lb or more should receive the adult dose.
The recommended dose of doxycycline for Post-Exposure Prophylaxis (PEP) is:
- Adults: 100 mg, by mouth, twice a day for 60 days
- Children:
- Weighing less than 100 lb (45 kg): 1 mg/lb (2.2 mg/kg) of body weight, by mouth, twice a day for 60 days
- Weighing 100 lb or more: same as adult dose 2
From the Research
Recommended Dose of Doxycycline for Post-Exposure Prophylaxis (PEP)
- The recommended dose of doxycycline for PEP is 200 mg taken up to 72 hours after condomless sex, as stated in the study 3.
- This dose has been shown to be effective in preventing syphilis, chlamydia, and to a lesser extent gonorrhea, in gay, bisexual and other men-who-have-sex-with-men (GBMSM) and transgender women 3.
- The efficacy of doxycycline PEP in preventing bacterial sexually transmitted infections (STIs) has been consistently demonstrated in recent studies, including randomized controlled trials and real-world analyses 4.
Considerations for Doxycycline PEP Implementation
- The potential benefits of doxycycline PEP, including STI prevention and holistic improvements in sexual health and wellbeing, must be weighed against concerns over emergent antimicrobial resistance 3.
- Inequities in the doxycycline PEP evidence-base and implementation may undermine its ability to effectively prevent STIs in certain populations, such as cisgender women 3.
- The impact of doxycycline PEP on the gut microbiome and antimicrobial resistome has been investigated, with findings suggesting an increase in the proportion of tetracycline ARGs comprising the gut resistome and an increase in the expression of tetracycline ARGs 5.
Awareness and Willingness to Use Doxycycline PEP
- Awareness and willingness to use doxycycline PEP among men who have sex with men (MSM) have been investigated, with findings suggesting high willingness to use doxycycline PEP, particularly among those with at-risk sexual behavior 6.
- Factors associated with willingness to use doxycycline PEP include engaging in anal sex, having fixed sexual partners, using recreational drugs, and receiving suggestions from healthcare providers 6.