Spotlight Center on HIV Prevention Today


Oral Pre-Exposure Prophylaxis (PrEP) Fact Sheet

June 2016

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Who Should Take PrEP?

PrEP should only be used by people who are HIV negative and at high risk for HIV infection. The Truvada product monograph recommends that the following factors may help to identify individuals at high risk:

A sexually active person who:

  • has partner(s) known to be living with HIV, or
  • engages in sexual activity within a high prevalence area or social network and one or more of the following:
    • inconsistent or no condom use
    • diagnosis of sexually transmitted infections
    • exchange of sex for commodities (such as money, food, shelter, or drugs)
    • use of illicit drugs or alcohol dependence
    • incarceration
    • partner(s) of unknown HIV status with any of the factors listed above

What Else Is Involved With Taking Oral PrEP?

Oral PrEP is part of a comprehensive HIV prevention strategy that includes safer sex practices and routine medical appointments.

The first step is to make sure a person is HIV negative before starting PrEP. They will also need to be tested for hepatitis B and other STIs and have their kidney function checked.

A person using oral PrEP needs to take Truvada as prescribed by their healthcare provider. In addition to taking the medication daily, they must also attend regular doctor's appointments, approximately every three months. These regular visits are necessary in order to be tested for HIV and other STIs, monitored for drug side effects, and receive ongoing adherence and risk-reduction counselling.


Is PrEP Intended to Replace Condoms and other HIV Prevention Strategies?

Oral PrEP is not intended to replace other HIV prevention strategies because it is not 100% effective, is substantially less effective if used inconsistently or incorrectly, and is not intended for everyone. PrEP can still be effective at reducing the risk of HIV infection when condoms are not used; however, guidelines recommend that PrEP be used in combination with safer sex practices and harm-reduction strategies to optimally reduce the risk of HIV infection.

PrEP only helps to prevent HIV and does not offer protection against STIs (such as herpes, chlamydia or syphilis) or blood-borne infections such as hepatitis C. Other prevention strategies (such as using condoms or new needles) are needed to reduce the risk of all other infections that can be passed through sex or sharing of injection drug use equipment.

What Are the Advantages of PrEP?

The main advantage of oral PrEP is that it adds another highly effective HIV prevention option to the growing list of prevention strategies. For example, PrEP may provide another method to help protect people who are unable to negotiate condom use with their partner(s), people in serodiscordant relationships (where one partner is HIV negative and the other is HIV positive), people who inject drugs but are not able to obtain new needles, or other people who do not use condoms or new needles consistently for whatever reason.

Another advantage is that daily oral PrEP use can be started during periods of higher risk and stopped during periods of lower risk.

What Are Some of the Safety Concerns Associated With Taking PrEP?

Drug Resistance

A person can develop resistance to the drugs in Truvada if they are HIV positive (and unaware of their positive status) when starting oral PrEP. Drug resistance can limit a person's future treatment options, so it is important to ensure that they are HIV negative before starting oral PrEP.

A person can also develop drug resistance if they become HIV positive while taking oral PrEP. In clinical trials, the risk of developing drug resistance was low for people who were HIV negative when starting PrEP.

Regular HIV testing is necessary while taking oral PrEP. If a person using PrEP becomes infected with HIV, PrEP use must be discontinued as soon as possible, to reduce the risk of developing drug resistance. If a person's HIV becomes resistant to the drugs in Truvada, those same drugs may not work to treat HIV.

Side Effects

Truvada may cause side effects, which may negatively affect a person's quality of life and ability to adhere to their medication schedule.

Although Truvada is generally better tolerated than some of the other drugs used to treat HIV, it is still capable of causing side effects. Some of the possible side effects include nausea, vomiting, diarrhea, headache and dizziness. In clinical trials these side effects were generally mild, temporary, and only affected between 1% and 10% of participants. PrEP may also cause small decreases in kidney, liver and bone health but in oral PrEP trials this did not lead to kidney or liver failure or bone fracture.

Although research suggests that the use of daily Truvada as PrEP is generally safe and well tolerated, the long-term effects of using PrEP are less well known.

Getting PrEP From Other Sources

Obtaining antiretroviral drugs from other sources -- from a friend, people at parties, or over the internet -- may be dangerous. Drugs obtained from these sources may be fake, of poor quality, or contain a different medication than expected. In addition, before starting oral PrEP, a person needs to have a thorough assessment by a doctor and be tested for HIV to make sure they are HIV negative.

Obtaining Truvada from a doctor will help ensure that a person is prescribed the right medication at a safe dose and provided with accurate information on how to use it safely and effectively.

How Can People at High Risk of HIV Infection Access PrEP?

An HIV-negative person who wants to take PrEP needs to get a prescription for Truvada from a doctor who is willing to provide the necessary medical follow-up in a safe and informed way. Health Canada has approved the prescription of Truvada as PrEP for reducing the risk of sexually acquired HIV infection, in combination with safer sex practices.

Not all doctors are knowledgeable about PrEP and it may be difficult for clients to find a doctor who is willing to prescribe Truvada as PrEP for HIV prevention.

Although the use of Truvada as PrEP has not been approved by Health Canada to reduce the risk of injection-related HIV transmission, healthcare providers can still prescribe it for this purpose. This is possible because Truvada has already been approved for PrEP to reduce the sexual transmission of HIV and the treatment of HIV. When an approved drug is prescribed for an unapproved use, this is called an "off-label" prescription. These types of prescriptions are legal and -- for some types of drugs -- common.

Antiretroviral drugs are expensive and Truvada as PrEP costs approximately $1000 a month. Currently, only some private and public health insurance plans in Canada will cover the cost of the drugs. PrEP was approved for prevention in Canada in February 2016 and we expect that more insurance coverage will eventually become available. Advocacy may be needed to get PrEP covered by all provincial and territorial drug programs to ensure that people who need PrEP can access it.

What Other Types of PrEP Are Out There?

Other types of PrEP, including vaginal or rectal gels, intravaginal rings and long-lasting injections are currently in experimental stages. No other forms of PrEP have been approved for use by any regulatory agency in the world, and we do not expect them to be available for use in Canada in the near future.

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This article was provided by Canadian AIDS Treatment Information Exchange. Visit CATIE's Web site to find out more about their activities, publications and services.

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