PrEP Regimen for Women
Women should receive daily oral TDF/FTC (tenofovir disoproxil fumarate 300mg/emtricitabine 200mg) taken at the same time every day, as this is the only validated and recommended regimen for preventing HIV acquisition through vaginal exposure. 1, 2
Critical Regimen Specifications
Daily dosing is mandatory for women — on-demand or event-driven PrEP (2-1-1 dosing) is NOT validated for vaginal exposures and should never be used in women, as tenofovir concentrates at lower levels in vaginal tissue compared to rectal tissue and has faster clearance. 3, 2
Time to Protection
- 7 days of daily dosing is required before full protection is achieved for vaginal exposures 2
- Start with a double dose (2 tablets) on day 1, followed by single daily tablets thereafter to achieve protective drug levels more rapidly 1, 2
- Continue daily dosing for at least 7 days after the last sexual activity when discontinuing PrEP 2
Alternative Regimen Considerations
TAF/FTC (tenofovir alafenamide/emtricitabine) should NOT be used in women — daily TAF/FTC is limited to cisgender men and others whose exposures do not include receptive vaginal sex, as it lacks validation for vaginal HIV prevention. 3, 2
When TAF/FTC Might Be Considered
Despite the above restriction, emerging pharmacokinetic data suggests TAF may achieve similar or higher tenofovir-diphosphate concentrations in vaginal tissue compared to TDF, with better tolerability (fewer gastrointestinal adverse events: 11.5% vs 44.0%). 4 However, this remains investigational and should not change current practice until clinical efficacy trials in women are completed.
Pre-Initiation Requirements
Before prescribing PrEP, the following assessments are mandatory: 1, 5
- HIV testing: Combined antibody/antigen assay (with HIV RNA if acute infection suspected) within 7 days of initiation 1, 2
- Renal function: Serum creatinine and calculated creatinine clearance 1
- Hepatitis B surface antigen (HBsAg) testing 1
- Hepatitis C antibody testing 1
- STI screening: Genital and non-genital testing 1
- Pregnancy testing for individuals of childbearing potential 5
Special Consideration for Pregnancy
TDF/FTC is safe during pregnancy and breastfeeding with no documented adverse fetal effects, and should be continued as the preferred regimen. 5 Benefits and risks should be discussed, but pregnancy is not a contraindication. 3
Monitoring Schedule
First Month
Every 3 Months
- HIV testing to ensure patient remains HIV-negative 1, 5
- STI screening 1, 5
- Pregnancy testing 5
- Assessment of adherence, side effects, and risk behaviors 3
Every 6 Months
- Creatinine assessment to monitor kidney function 1, 5
- More frequent monitoring if baseline creatinine clearance <90 mL/min or presence of diabetes/hypertension 5
Prescribing Limits
Critical Pitfalls to Avoid
Never use on-demand/event-driven PrEP in women — this dosing strategy (2-1-1) has only been validated in cisgender men and transgender women for rectal exposures, not vaginal exposures. 3, 2
Do not start PrEP if acute HIV infection is suspected — defer until HIV-negative status is confirmed, especially if symptoms present (fever, headache, muscle soreness, sore throat, rash, swollen lymph nodes). 3
Monitor for hepatitis B flares if discontinuing PrEP — in HBsAg-positive women, consider indefinite continuation or transition to hepatitis B treatment, with close ALT/AST monitoring after discontinuation. 5
Ensure adequate lead-in time — women must understand that 7 days of daily dosing is required before protection is achieved, unlike the 2-3 days needed for rectal exposures. 2
Adherence Support
Adherence is critical for efficacy (>90% protection with consistent use). 1, 5 Implement: 3
- Education about the importance of daily dosing
- Pill reminders (electronic device alarms)
- Behavioral interventions
- If a dose is missed, take it immediately when remembered 3