What are the recommendations for routine screening and Pre-Exposure Prophylaxis (PrEP) with medications such as Truvada (emtricitabine/tenofovir disoproxil fumarate) or Descovy (emtricitabine/tenofovir alafenamide) for men who have sex with men?

Routine Screening and PrEP Medications for Men Who Have Sex with Men

For MSM at risk of HIV, prescribe daily oral emtricitabine/tenofovir disoproxil fumarate (Truvada) as first-line PrEP, with quarterly HIV and STI screening at all potentially exposed anatomic sites (oral, rectal, and urogenital). 1

PrEP Medication Selection

First-Line: Truvada (TDF/Emtricitabine)

• Daily oral TDF/emtricitabine is the recommended PrEP regimen for MSM with proven efficacy in preventing HIV acquisition 1
• Prescribe one tablet daily (emtricitabine 200 mg/tenofovir disoproxil fumarate 300 mg) 2
• A 1-week lead-in period is recommended before adequate tissue levels are achieved for rectal and penile exposures 1
• Continue for 1 week after the last sexual exposure when discontinuing 1

Alternative: Descovy (TAF/Emtricitabine)

• Descovy (emtricitabine 200 mg/tenofovir alafenamide 25 mg) is specifically indicated for MSM with renal impairment (creatinine clearance 30-60 mL/min), osteopenia, or osteoporosis 3
• Take one tablet orally once daily—no loading dose required 3
• Critical limitation: Descovy is NOT recommended for cisgender women or event-driven "2-1-1" dosing 3

Event-Driven PrEP Option

• Pericoital "2-1-1" dosing with TDF/emtricitabine may be considered for MSM with infrequent sexual exposures: 2 tablets 2-24 hours before sex, 1 tablet 24 hours after the first dose, and 1 tablet 48 hours after the first dose 1
• This regimen is NOT recommended for individuals with active hepatitis B infection due to risk of hepatic flare 1

Pre-Initiation Testing Requirements

Before starting PrEP, obtain the following mandatory tests 1:

• HIV testing with combination antigen-antibody assay (if acute HIV suspected, add HIV RNA testing) 1
• Serum creatinine and estimated creatinine clearance (do not start TDF-based PrEP if <60 mL/min) 1
• Hepatitis B surface antigen (HBsAg) 1
• Hepatitis C antibody 1
• STI screening at all potentially exposed sites:
  • Rectal, pharyngeal, and urogenital nucleic acid amplification testing (NAAT) for gonorrhea and chlamydia 1, 4
  • Syphilis serology 1

Vaccination Recommendations

• Hepatitis A and B vaccination for those not immune 1
• HPV vaccination for men aged 13-26 years who have not completed the 3-dose series 1

Ongoing Monitoring Schedule

Every 3 Months (Quarterly)

• HIV testing with combination antigen-antibody assay 1
• Three-site STI screening (rectal, pharyngeal, urogenital) for gonorrhea and chlamydia by NAAT 1, 4
• Syphilis serology 1
• Adherence assessment and counseling 1
• PrEP prescriptions should not exceed 90 days without interval HIV testing 1

Every 6-12 Months

• Serum creatinine and estimated glomerular filtration rate 1
• More frequent renal monitoring (every 3-6 months) for patients >50 years, taking hypertension/diabetes medications, or with baseline eGFR <90 mL/min 1
• Hepatitis C serology (at least annually, more frequently if elevated transaminases or injection drug use) 1

One Month After Initiation

• Follow-up visit for HIV testing, adverse effect assessment, and adherence support 1

Clinical Rationale for Three-Site STI Testing

Testing only genital sites misses the majority of infections in MSM 4:

• In one PrEP clinic study, 30.5% of MSM had STIs during follow-up, with 10 oropharyngeal gonorrhea, 8 anorectal gonorrhea, 12 anorectal chlamydia infections—all extragenital infections were asymptomatic 4
• Among MSM tested comprehensively, only 48% were tested from genital sites alone, while 25% received appropriate three-site testing 5
• Rectal chlamydia positivity was 9.8%, rectal gonorrhea 7.3%, and pharyngeal gonorrhea 5.3% 5

Important Contraindications and Cautions

Do Not Prescribe TDF-Based PrEP If:

• Creatinine clearance <60 mL/min 1
• Osteopenia or osteoporosis (use Descovy instead for MSM) 1, 3
• HIV infection is confirmed or suspected 3

Special Hepatitis B Considerations

• Use caution when discontinuing TDF/emtricitabine in patients with chronic hepatitis B—risk of acute flares or hepatic decompensation, particularly with cirrhosis 1
• Monitor HBV infection and liver function carefully after discontinuation 1

If HIV Infection Occurs During PrEP

• Immediately add a boosted protease inhibitor (darunavir/ritonavir or darunavir/cobicistat) and/or dolutegravir to TDF/emtricitabine while awaiting HIV RNA and resistance testing results 1
• Switch to a recommended initial antiretroviral regimen once HIV is confirmed 1

Key Clinical Pitfalls to Avoid

1. Do not rely on genital-only STI testing—you will miss 50-70% of infections in MSM 5, 4
2. Do not prescribe Descovy to cisgender women—efficacy has not been demonstrated 3
3. Do not use event-driven dosing in patients with hepatitis B—risk of hepatic decompensation 1
4. Do not extend PrEP prescriptions beyond 90 days without HIV testing—risk of undetected seroconversion 1
5. Do not forget the 1-week lead-in and tail periods for TDF/emtricitabine to ensure adequate tissue drug levels 1