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Who should take PrEP?

Who should take PrEP?

Updated on:
August 3, 2021

When it comes to determining if PrEP is right for you, it's first essential to understand one’s risk for HIV. Since HIV is transmitted through bodily fluids that carry the virus, anything that can facilitate the entrance of HIV into your bloodstream can increase your risk of transmission. 

What factors play a role in my risk for HIV?

Some considerations that may increase your likelihood of contracting HIV are: presence of other STIs, using drugs, the type of sex your having, partner(s) STI history, etc. For some more practical examples, please find below some questions often asked during PrEP consultations and sexual health history. 

  • Do you sometimes have sex without condoms?
  • Do you have sex partner(s) whose HIV status you don’t know?
  • Do you have sex partner(s) who are HIV positive but are not virally suppressed?
  • Have you had a sexually transmitted infection (STI) in the past year?
  • Have you used post-exposure prophylaxis (PEP) more than once?
  • Do you ever share equipment for injection drug use?

PrEP is used by HIV negative people who are at high risk for HIV infection. According to Canadian statistics, some communities at higher HIV risk are:

1) Men or trans women who report condomless anal sex with men and have any of the following:

  • Infectious syphilis or bacterial STI in the last year
  • Use of post-exposure prophylaxis (PEP) more than once
  • A high score on a valid HIV risk assessment tool

2) Any person who has condomless anal or vaginal sex with a partner who HIV positive who is not on treatment and virally suppressed

3) People who share injection drug use equipment

Although the criteria above are a good starting point to determine PrEP eligibility, it should not be used to deny someone access to PrEP. There are many reasons why somebody may choose to be on PrEP and different behaviour which may put you at higher HIV risk. For example, the Canadian PrEP guideline says: “When considering PrEP for heterosexual adults on the basis of having multiple or unknown-status partners, practitioners must make decisions on a case-by-case basis, using local epidemiologic data and patient-reported risk behaviours/exposures in the partner”.
In short, there are many reasons why somebody would choose to be on PrEP. The decision is made between you and a healthcare provider based on your risk for HIV.

PrEP is for men who have sex with men, transgender women, and gender diverse communities

Trans women who are at higher risk for HIV are recommended to be on PrEP according to Canada’s PrEP guidelines. HIV disproportionately impacts Trans women, especially those in sex work and trans women of colour. Some reasons for that are the unequal access to healthcare, education, and overall marginalization of trans and gender diverse people. Research and academic studies, as well as surveillance data in Canada, largely invisibilize trans communities, contributing to worse health outcomes like increased rates of HIV and STIs.

When compared to MSM (men who have sex with men), trans women demonstrated lower PrEP adherence and less consistent use of PrEP over time. Trans women were also more likely to report transactional sex, condomless receptive anal sex, and having more than five partners in the past three months. 

Evidence from the iPREX study suggests that PrEP barriers among trans women may be due to a lack of trans-inclusive and culturally competent services, lack of trust with service providers, and concerns about PrEP interactions with gender-affirming hormones.

Based on current studies, no drug interactions are expected between masculinizing or feminizing hormones and PrEP based on the available evidence. This is because hormones are metabolized by the liver, whereas the drugs in PrEP are processed in the kidneys, decreasing the likelihood of interactions between the drugs.

Studies on the effectiveness of PrEP in trans men are ongoing, but this population has been largely excluded from PrEP studies. Trans men may be at higher risk for HIV, particularly if they have sex with other men. Despite limited evidence, there is reason to believe that PrEP is highly effective when taken as prescribed by trans men. In order to reach optimal effectiveness from PrEP, the rule remains the same as it depends on the type of sex they you are having. It can take about 7 days for PrEP to reach optimal concentration for anal sex, and about 21 days for vaginal/frontal sex.

In general, studies show that trans individuals have concerns about the safety and efficacy of PrEP, given the lack of research and healthcare access among this population.

PrEP is for people who use/inject drugs

People who use drugs, as well as people who share injecting drug equipment, can be considered at higher HIV risk. Canada’s PrEP guidelines recommend PrEP for this population (if they share injection drug use equipment or participate in sexual practices that place them at high risk for HIV), however PrEP has not been widely taken up by people who inject drugs. The way through which HIV is transmitted is different in needle sharing than through sex, because HIV has direct access to the blood stream when needle sharing takes place.

Studies demonstrate that PrEP does work to prevent HIV for people who inject drugs when adherence is high. Although the vast majority of PrEP studies have looked at preventing sexual HIV transmission, one major PrEP study was done with people who inject drugs. The Bangkok Tenofovir Study found an 84% reduced risk of getting HIV among people who inject drugs and were highly adherent to daily PrEP. Although this level of protection is not as high as some other PrEP studies, one possible explanation is that it only considered one PrEP component, TDF (rather than TDF + FTC), which is not the standard of care for oral PrEP.

It is important to note that combination prevention, that is, the use of multiple HIV prevention strategies simultaneously, can decrease one’s risk of getting HIV. So, PrEP, as well as condoms, HIV treatment, STI testing, needle distribution programs, and other harm reduction methods can provide a more effective and complete prevention strategy.

Reviewed by:
Dr. Caley Shukalek

Caley is passionate about evidence-based, patient-centred care, including telemedicine that can provide high quality care from wherever a patient may choose.

He helped create Alberta's PrEP guidelines and works as a specialist in General Internal Medicine with additional training in sexual health, including HIV and sexually transmitted infections.

He holds an Masters of Public Health from Johns Hopkins University, an MD from the University of Calgary and an MSc from the University of Alberta.