A Summary For Clinicians
What Is HIV PrEP?
PrEP is the administration of a combination anti-retroviral medication (tenofovir DF/ emtricitabine 300/200 mg, Truvada) to HIV-uninfected individuals at high and ongoing risk of HIV acquisition to prevent HIV.
Who Should Be Considered For HIV PrEP?
- PrEP is recommended for gbMSM and trans females with a HIRI-MSM score > 10 – 11.
- PrEP is recommended for gbMSM and trans females who have had condomless anal intercourse within 12 months AND have infectious syphilis or rectal STI OR have recurrent use of HIV post-exposure prophylaxis OR have an ongoing sexual relationship with HIV + partner with viral load > 40 copies/mL.
- PrEP is recommended for the HIV-negative partner in a heterosexual serodiscordant relationship where condomless anal or vaginal sex is occurring in the context of a substantial or non-negligible risk of transmission (negligible risk is defined as some with a viral load < 40 copies/mL AND no known STIs present at time of exposure).
- PrEP may be considered for individuals who use injection drugs if they share injection drug use paraphernalia.
What Is The HIRI-MSM?
The HIV Incidence Risk Index for MSM (HIRI-MSM) is a validated risk tool. A score of 10 corresponds with a 2% annual risk of HIV acquisition; a score of 25 corresponds with a 7% annual risk.
(source: Tan DHS, Hull MW, Yoong D, et al, 2017, Appendix 1 p.37)
How Much Does PrEP Cost?
Tenofovir DF/emtricitabine 300/200 mg (Truvada) is covered under the ODB formulary, and Trillium coverage can be obtained by most individuals without private or public drug benefits.
What Are The Most Common Side Effects And Possible Risks Of PrEP?
Truvada is extremely well tolerated, with some minor transient gastrointestinal symptoms and headache possible in the first week. There can be some impacts on bone density that appear reversible upon discontinuation. Renal function needs to be monitored.
Truvada is a treatment for hepatitis B, and discontinuing it in someone who has Hepatitis B can cause a flare; Hepatitis B screening is part of the initial work up, and vaccination is recommended in individuals who are non-immune.
If an individual taking PrEP acquires HIV, they may develop drug-resistant infection. Anyone with symptoms of acute retroviral syndrome (fever, headache, myalgia, sore throat) should be assessed and tested.
What Baseline Testing And Monitoring Should Be Done?
(source: Tan DHS, Hull MW, Yoong D, et al, 2017, p. E1453)
Tan DHS, Hull MW, Yoong D, et al. Canadian Guidelines on HIV pre-exposure prophylaxis and non-occupational postexposure prophylaxis. CMAJ. 2017. 189:E1448-58. doi: 10.1503/cmaj.170494
Appendix to: Tan DHS, Hull MW, Yoong D, et al. Canadian Guidelines on HIV pre-exposure prophylaxis and non-occupational postexposure prophylaxis. CMAJ. 2017. Doi: 10.1503/cmaj