Pre-exposure Prophylaxis (PrEP)

Principles & Procedure

1

PrEP should be offered to sexually active individuals likely to be exposed to HIV when condoms are not used consistently. Before or on the day PrEP is initiated, HBV serology status should be documented

2

PrEP is a medical intervention that provides a high level of protection against HIV acquisition but does not protect against other STIs or pregnancy and should be used in combination with other preventive interventions. PrEP should be supervised by a doctor, experienced with sexual health and use of HIV medicines, possibly as part of a shared care arrangement

Recommended Procedures

• Documented negative fourth generation HIV test a week prior or on the day PrEP is initiated. In case of suspicion of acute HIV-infection, an RNA test on plasma should also be performed, see Primary HIV Infection (PHI). During PrEP, a fourth generation HIV test should be repeated at one month and then every 3 months. In stable long-term users who are on 6 monthly prescriptions an interim fourth generation test that can be performed without a visit to clinic
• PrEP should be changed to triple-drug ART without interruption in case of early clinical signs of HIV seroconversion or a positive HIV diagnostic test which may necessitate referral for evaluation to an HIV unit, see ART initiation 
• PrEP may continue during pregnancy and breastfeeding if the risk of acquiring HIV persists
• Before or on the day PrEP is initiated, HBV serology status should be documented. If HBsAg positive, see Clinical Management and Treatment of HBV and HCV Co-infection. 
• Counsel that PrEP does not prevent other types of STIs; screen for STI (syphilis, chlamydia, gonorrhoeae, HAV, HCV) when starting PrEP and regularly during use of PrEP, see Assessment of Initial & Subsequent Visits. All persons taking PrEP should be offered vaccinations against HAV, HBV, HPV and mpox virus. Doxycycline post exposure prophylaxis, 200 mg within 24 to 72h after sexual intercourse, proved to be effective in preventing bacterial STIs in MSM with the caveat of the unknown long terms effects on microbiota and STIs resistance. It can be proposed to persons with repeated STIs.
• Counsel that TDF-based PrEP may rarely impact renal and bone health, see Bone Disease: Screening and Diagnosis, Approach to Fracture Reduction, Kidney Disease: Definition, Diagnosis and Management, ARV-associated Nephrotoxicity. Check renal function within the first 3 months of starting PrEP and check renal function and bone health during PrEP according to guidelines on TDF use
• Counsel that PrEP, like other prevention methods, only works when it is taken. An adherence check one month after starting is recommended, and counselling may be required during follow-up
• Counsel that PrEP can be prescribed long-term but that each consecutive PrEP prescription should cover the period to the next visit which will be every 3 months for the majority but could be a maximum of 6 months in stable long-term users (over one year of daily PrEP)
  
  

3

PrEP regimen

• Regimens: DAILY TDF/FTC 300*/200mg 1 tablet qd and ON-DEMAND double dose of TDF/FTC 24 hours before exposure, followed by two single doses of TDF/FTC, 24 and 48 hours after the first dosing
• Starting: clinical (male) and pharmacokinetic/pharmacodynamic studies (non-male) studies support all populations starting TDF/FTC PrEP with two tablets taken together as this achieves highly effective levels in all compartments 2 hours later
• Stopping (male): clinical studies support men stopping TDF/FTC PrEP by taking two single doses 24 and 48 hours after the last sexual intercourse
• Stopping (non-male populations): pharmacokinetic/pharmacodynamic studies support other populations stopping TDF/FTC PrEP by taking TDF/FTC daily for 7 days after the last exposure
• PK/PD studies comparing TAF/FTC to TDF/FTC suggest that the recommendations for starting and stopping TAF/FTC can be extrapolated from TDF/FTC
• Use of generic formulations of TDF/FTC, if and where available, may help to improve the cost-effectiveness of PrEP, which is essential for its use as public health approach
• Rates of adverse eGFR declines are generally low for those using TDF for PrEP, but PrEP users with the highest risk of adverse renal outcomes on TDF and most in need for systematic monitoring of renal function are older individuals (> 50 years) and those with pre-existing renal impairment. On demand PrEP may improve renal outcomes vs daily PrEP. Data on renal outcomes with use of TDF vs. TAF in those on PrEP with renal impairment is limited, recommendations to follow guidelines on TDF use in persons with HIV, see Kidney Disease: Definition, Diagnosis and Management, ARV-associated Nephrotoxicity, Indications and Tests for Proximal Renal Tubulopathy (PRT). 
• Any person presenting with low PrEP adherence and a condomless at risk sexual intercourse should benefit from post exposure prophylaxis. Low adherence is defined:
  -  For men and women on daily regimen: less than 4 pills a week, regardless of the distribution
  -  For men on on demand regimen: non compliance to the 2-1-1 scheme