STD Prophylaxis Dosing Regimens for Adult Males
For sexually transmitted disease (STD) prophylaxis in adult males, the recommended regimens depend on the specific infection being targeted, with doxycycline 200 mg as a single dose after sexual exposure being the most current evidence-based approach for bacterial STI prevention.
Bacterial STI Post-Exposure Prophylaxis (DoxyPEP)
- Doxycycline 200 mg taken as a single dose as soon as possible (within 72 hours) after condomless sexual exposure is recommended for men who have sex with men (MSM) and transgender women with a history of bacterial STIs in the past 12 months 1
- This approach (doxyPEP) reduces the incidence of chlamydia by 70-88% and early syphilis by 73-87%, with less consistent effects on gonorrhea 1
- DoxyPEP can be prescribed in quantities of 30 doses (60 tablets/capsules) at a time to allow for ongoing protection 1
- Regular STI screening (quarterly) is recommended for individuals using doxyPEP 1
Non-Gonococcal Urethritis (NGU) Treatment
- Doxycycline 100 mg orally twice daily for 7 days is the recommended first-line regimen for NGU 1
- Alternative regimens include:
Gonorrhea Treatment
- Current recommendation for gonorrhea is ceftriaxone monotherapy given intramuscularly, with dosing based on the patient's body weight 2
- For suspected gonococcal infection, the CDC recommends antimicrobial therapy with ceftriaxone 3
Chlamydia Treatment
- Doxycycline 100 mg orally twice daily for 7 days is the preferred treatment for chlamydial infections 1, 2
- A test-of-cure is recommended for rectal chlamydia if treated with azithromycin 2
Syphilis Treatment
- For syphilis of less than one year's duration: Single dose of intramuscular penicillin G benzathine, 2.4 million units 2
- For syphilis of more than one year's or unknown duration: Three consecutive weekly doses of intramuscular penicillin G benzathine, 2.4 million units each 2
HIV Pre-Exposure Prophylaxis (PrEP)
- Daily oral TDF/FTC (tenofovir disoproxil fumarate/emtricitabine) remains a recommended oral PrEP regimen for all populations at risk for HIV exposure 1
- On-demand (2-1-1) oral dosing of TDF/FTC is recommended for cisgender men having planned receptive anal sex:
- Double dose 2-24 hours before sexual activity
- Single additional doses 24 and 48 hours after the first dose 1
- Daily oral TAF/FTC (tenofovir alafenamide/emtricitabine) should be limited to cisgender men whose exposures do not include receptive vaginal sex or injection drug use 1
Hepatitis Prophylaxis
- Hepatitis B vaccination is recommended for:
- Persons seeking evaluation or treatment for STDs
- Men who have sex with men
- Persons with multiple sexual partners
- Persons who are not in long-term, mutually monogamous relationships 1
- Hepatitis A vaccination is recommended for men who have sex with men and persons who use illegal drugs 1
Clinical Considerations and Monitoring
- For patients with persistent or recurrent urethritis, retreatment with the initial regimen is recommended if they failed to comply with treatment or were re-exposed to an untreated partner 1
- Men should be instructed to abstain from sexual intercourse for 7 days after single-dose therapy or until completion of a 7-day regimen, provided their symptoms have resolved 1
- Regular STI screening is essential for high-risk individuals, particularly MSM with bacterial STDs who are at elevated risk for HIV 4
Important Caveats
- Breakthrough syphilis infections while using doxyPEP may have aberrant or attenuated rapid plasma reagin characteristics 1
- The long-term effects of doxyPEP on bacterial resistance to tetracyclines remains an unresolved concern that should be monitored 1
- When prescribing prophylaxis, clinicians should be aware that many patients confuse bacterial STI prevention with HIV prevention 5