What is PrEP?
PrEP is short for Pre-Exposure Prophylaxis. PrEP is a pill that reduces your risk of getting HIV through sex by up to 99% when taken as prescribed. The presence of the medicine in your bloodstream helps stop HIV from getting into your cells and spreading throughout the body. This ensures you remain HIV-negative.
Who is PrEP for?
PrEP can be taken by anyone who is HIV-negative and at higher risk for HIV. PrEP may be a fit for you if you:
- don’t always use condoms
- share drug injection equipment
- don’t know the HIV status of your sexual partners
- have more than one partner or have anonymous sexual encounters
- tested positive for infectious syphilis, chlamydia or gonorrhea in the last year
- have used post-exposure prophylaxis (PEP) more than once
- do in-person sex work
Types of PrEP
In Canada, there are two different medications used to prevent HIV: Truvada and Descovy. They both offer 99% protection when taken as prescribed. Both of these medications contain two different drugs. Your clinician will review your file and discuss your options with you.
- Truvada contains a drug (TDF) that may affect bone and kidney health, so patients with existing bone or kidney conditions (like osteoporosis or kidney disease) are not recommended to take Truvada.
- Truvada can be taken by ALL patients regardless of anatomy
- Truvada can be taken daily or on demand. For more information, see our article "PrEP On-Demand (PrOD)" elsewhere in this help centre. Please note that PrOD requires a virtual appointment with our clinical staff.
- Descovy contains a newer version of TDF (called TAF) to help patients avoid the side effects on kidney function and bone health.
- Descovy is also known to have less side effects on start-up.
- Descovy is currently contraindicated in those with vaginal tissue. This means it's not recommended for HIV prevention if you have a vagina and have vaginal (front) sex.
- Descovy must be taken daily.
Daily PrEP dosing
- Take one pill by mouth at same time each day
- If you miss a dose, take the tablet as soon as you remember. If it is less than 12 hours until your next dose, wait until your next dose. Do not double dose.
- Tablet can be taken with or without food.
Side effects/safety information:
- Only 1-10% of patients on PrEP experience side effects. Most symptoms tend to go away within one to two weeks naturally. Possible side effects are diarrhea, nausea, abdominal pain, headache, fatigue.
- Taking PrEP as prescribed gives 99% protection, this decreases if not taken as directed.
- To get full protection from daily PrEP, it takes:
- Seven days to achieve protective levels in anal tissue (for anal sex)
- 21 days in vaginal tissue (for front sex).
- PrEP does not protect against sexually transmitted infections (STIs) other than HIV and has no contraceptive effect. To prevent STIs and pregnancy, you can use condoms.
- We recommend adequate calcium and vitamin D intake while on PrEP. Health Canada recommends 1000 mg/day dietary intake of calcium and 600 IU/day vitamin D in most adults. Regular exercise is also encouraged for maintenance of bone health.
- We suggest using NSAIDs (e.g. Ibuprofen or Alieve, Tylenol is not an NSAID) sparingly while on Truvada.
- If you plan on stopping PrEP, please let us know through the Freddie portal for instructions and safety information.
Regular lab work is required at least every three months while on PrEP.
- When you start PrEP, we will test for kidney function, HIV, hepatitis A/B (including immunity status), hepatitis C, syphilis, chlamydia and gonorrhea.
- Every three months we check your kidney function and test for HIV and STIs (please note that you will need to ask specifically for throat and rectal STI testing)
- Once we get your results, we will contact you if your kidney results are abnormal or any STI tests come back positive. If you don't hear from us, then that's good news! If you do test positive, we can connect you with treatment.
Most private insurance companies cover Truvada. Provincial coverage of generic Truvada varies by province, with the majority providing some or all funding towards medication coverage. About 85% of private insurance companies cover Descovy. In addition, Descovy’s drug manufacturer (Gilead) offers a patient support program that covers up to 30% of co-pay cost on top of your insurance, meaning most patients get Descovy totally for free. The pharmacy will check your insurance coverage and apply for the co-pay coverage through Gilead for you and will let you know if there are any uncovered costs prior to dispensing the medication.