Pre-Exposure Prophylaxis (PrEP)
What is PrEP?
PrEP, short for pre-exposure prophylaxis, is a medication taken as a once-daily pill used by HIV-negative individuals who are at high risk of infection in order to decrease their risk of getting infected with HIV. It is a combination of two antiretroviral drugs: tenofovir and emtricitabine. These drugs are combined to make one pill, sold either as Truvada or as a generic form. This medication is also sometimes used to treat people with HIV infection. It is very effective at preventing HIV infection when taken every day as prescribed.
How do I use PrEP?
PrEP is taken once daily by mouth. Taking the pill once a day ensures the drug levels are high enough in your body to reduce the chance of infection. It is important to take the pill every day as prescribed. You may hear of people taking PrEP on and off (intermittent or on-demand PrEP). Talk to your doctor before making any changes to how you take your PrEP, since that can change how well it works.
How can I pay for PrEP?
PrEP is covered by many plans that you may be eligible for. If you are 24 and under, over 65, are on Ontario Works or the Ontario Disability Support Program, or have the Trillium Drug Plan, you can qualify for PrEP through the Ontario Drug Benefit. If you have private insurance through your work or school, or through a family member with a plan, you likely can have PrEP covered through that plan. If you don’t qualify through either of these methods, you can apply for the Trillium Drug Plan for help in covering the cost as long as you have an OHIP card. Ask our clinic staff if you need help applying to this program, or if you have other questions about covering the cost of PrEP.
What do I do if I miss a pill?
If you miss one pill but remember to take it within 12 hours, take it as soon as you remember, then go back to taking it at your usual time.If it is between 12to 24 hours, wait until your usual time that you take PrEP and take your next scheduled pill as usual.If you miss more than one dose, call KFL&A Public Health to discuss during weekday hours. If it is the evening or weekend, take one pill and then go back to taking it at your usual time, use backup protection during any risky activity, and call KFL&A Public Health as soon as you can to discuss.
It is important to remember that PrEP is not as effective if you miss doses.
How well does it work?
PrEP has been shown to be very effective at preventing HIV infection if taken once daily. Different studies have given different estimates. PrEP reduces the risk of HIV transmission in men who have sex with men (MSM)between around 85 to 92 percent if taken daily. This number is lower when pills are missed or forgotten.We have less evidence for people in heterosexual relationships where one person has HIV and the other doesn’t or for people who use injection drugs, but our best estimates still show a large reduction in risk.
That said, PrEP isn’t 100 percent perfect. There are rare cases where people have taken their PrEP perfectly and still get HIV. Also, PrEP doesn’t work as well when you forget or miss doses. This is why it is important to use PrEP as prescribed.
How soon does it work?
When someone is taking PrEP regularly for prevention of HIV transmission through anal intercourse, it starts working to prevent infection around 7 days. For vaginal or front hole intercourse, or blood-based transmission it takes longer, probably around 20 days.
What follow up do you need for PrEP?
The first testing you need before starting PrEP is baseline HIV, Hepatitis A/B/C, and syphilis blood testing, as well as blood tests for your kidney function. Other screening for sexually transmitted infections, like gonorrhea, will be done based on your specific sexual behaviours.
Once this has been done you will either have a phone call telling you either to start your PrEP, or that we need you to come in sooner for follow up based on your test results before starting PrEP.
After starting PrEP, you will need a follow up appointment and blood testing around a month later to make sure things are going well. After that, you will need to have follow up appointments and blood work every three months.
Are there any side effects?
PrEP is generally well tolerated by most people. Less than 10 percent of people experience symptoms when starting PrEP; these can include nausea, vomiting, diarrhea, headache, and dizziness. These side effects are usually mild and temporary. If you have any concerning side effects after starting PrEP, contact KFL&A Public Health for advice or if you feel very unwell you can access emergency care.
Some people develop changes in their kidney and bone health over time. In the PrEP trials that have been done, these have been mild and reversible after stopping PrEP, but this is why it is important to get regular blood work to check on your kidneys. Because PrEP is so new, we don’t have long-term studies yet to know the impacts of being on PrEP for a long time.
Does PrEP protect against other infections?
No, PrEPis not effective at preventing any other sexually transmitted or blood borne infections. This is why it is important to keep other prevention methods in mind, like using condoms and using new equipment for any drug use. PrEP is one of many prevention strategies we have, and it’s important to choose the set of strategies that works for you. Canadian guidelines recommend PrEP is used in combination with other safer sex practices and harm reduction strategies. This is because of other infections, and because PrEP, while very effective, is still not 100 percent effective at preventing HIV transmission.
When do I stop PrEP?
If you no longer are at high risk for HIV infection then you no longer need PrEP. If you are thinking about stopping your PrEP, call KFL&A Public Health to book an appointment to discuss with a member of our team. We can help you determine your risk status and whether stopping is the right choice for you.
Please don’t stop or intermittently take your PrEP without discussing first with one of our team members
What if I have other questions or concerns?
You can always call KFL&A Public Health at 613-549-1232 to discuss any questions or concerns that pop up
from 9 a.m. to 12 p.m. and 1 to 4 p.m., Monday to Friday. If you are feeling unwell, you should seek urgent
care through your family doctor, at the emergency room, or at an urgent care centre and let them know you are on PrEP.