Pre-exposure prophylaxis for HIV

From IDWiki

Background

  • Principle: give HIV meds to high-risk individuals to prevent seroconversion if exposed
  • Works when adherent, but adherence is often poor

Management

Assessing Eligibility

  • MSM: condomless anal sex within the last 6 months, and any of:
    • Sexually transmitted infection within the last 12 months
    • Recurrent use of HIV PEP at least twice
    • Ongoing sexual relationship with an HIV-positive partner who has a detectable viral load or is not on treatment
      • Stop if partner is undetectable for 6 months
    • HIV incidence risk index for men who have sex with men (HIRI-MSM) ≥11
  • Heterosexual exposure
    • Ongoing condomless sexual relationship with an HIV-positive partner who has a detectable viral load or is not on treatment
      • Stop if partner is undetectable for 6 months
    • Can be considered even if condomless sexual relationship with an HIV-positive partner with low risk
  • People who inject drugs
    • Consider if they share drug paraphernalia with someone who has risk of HIV
    • People who inject drugs may not benefit as much

Baseline Investigations

Treatment

  • First-line, continuous: tenofovir disoproxil fumarate/emtricitabine 300 mg/200 mg daily
  • Alternative, continuous: tenofovir alafenamide/emtricitabine 25 mg/200 mg PO daily, if they can afford it
  • Alternative, on-demand (2-1-1): tenofovir disoproxil fumarate/emtricitabine 300 mg/200 mg two pills taken 2 to 24 hours before first exposure and continued daily until 48 hours after last exposure
  • Continuous prophylaxis should be prescribed for 3 months at a time without repeats, with follow-up every 3 months to give a new prescription
  • Connect to mental health and other services, if indicated
  • For continuous PrEP, wait 7 days before condomless sex if topping or 2 to 3 weeks if bottomming
    • Counsel on condom use and side effects

Follow-Up

  • Follow-up after 30 days and then every 3 months thereafter
Item Baseline 30 days q3mo q12mo
Clinical Evaluation
Symptoms of HIV seroconverion X X X
PrEP adherence and side effects X X
Assess indication for PrEP X X X
Counsel on prevention of HIV and STIs X X X
Assess and manage other syndemic conditions, including drug and alcohol use X X X
Laboratory Evaluation
HIV test X X X
Hepatitis A immunity X
Hepatitis B screen X if unvaccinated
Hepatitis C screen X
Screen for gonorrhea and chlamydia X X
Syphilis serology X X
CBC X X
Creatinine X X X
Urinalysis X
Pregnancy test (if appropriate) X X

Further Reading

  • Canadian guideline on HIV pre-exposure prophylaxis and nonoccupational postexposure prophylaxis. CMAJ. 2017;189(47):e1448-e1458. doi: 10.1503/cmaj.170494