The Importance of Adherence
PrEP’s effectiveness at preventing HIV infection is directly linked to how adherent you are (or how faithful you are in taking PrEP every day as prescribed). Only a handful of PrEP users demonstrated to be taking PrEP daily as prescribed have ever been infected with HIV. Most of those cases were likely due to an extremely rare scenario where the strain of HIV they were infected with was resistant to the two medications present in PrEP (More on that here, here, and here).
However, the more doses you miss, the less benefit PrEP provides. For example, in the iPrEX OLE trial there was a significant decrease in HIV risk reduction amongst those who only took 2-3 pills per week when compared to those who took four or more pills per week. The effectiveness decreased even further for those who took less than 2 pills per week.
Fortunately, both demonstration projects and real-word PrEP data have demonstrated that those who commit to taking PrEP demonstrate a high level of adherence. Additionally, specialized health clinics with large numbers of patients taking PrEP have reported no HIV infections amongst their PrEP patients despite a reasonably high rate of other STIs, reaffirming both the effectiveness of PrEP as an HIV prevention tool and the likely high rate of adherence demonstrated by those taking PrEP.
If you find that you experience challenges taking PrEP daily as prescribed, make sure you speak to your healthcare provider. They can help you develop strategies to make taking PrEP daily easier for you. Furthermore, if a high level of PrEP adherence is still challenging for you, you may want to speak to your healthcare provider about the possibility of taking PrEP intermittently (as discussed briefly below). Otherwise, if PrEP adherence is not possible for you, it might be best to look at other effective HIV prevention strategies.
Remember, if you’re on PrEP and don’t take it as prescribed, it won’t be as effective as it can be. This might provide you with a false sense of security. If that’s the case, it’s probably a good idea for you to discuss other HIV prevention strategies with your healthcare provider, including the use of barrier methods such as condoms, ensuring that both you and your partners test regularly for HIV and STIs, and to ensure that HIV-positive partners are on treatment and have attained an undetectable viral load.
Finally, some research has demonstrated that PrEP can also be effective at preventing HIV infection when taken intermittently or “on-demand.” Although some individuals are choosing to take PrEP this way, it is important that both you and your physician understand the "ins and outs" of intermittent PrEP use. Most medical guidelines still support the daily use of PrEP, recognizing that more research may be required to fully understand the various nuances of intermittent PrEP use. So, although we encourage taking PrEP daily as prescribed, if you and your healthcare provider wish to look closer at intermittent PrEP options, you can review the guidance provided in the Albertan PrEP guidelines.
Ongoing Monitoring & Follow-Up
In addition to things you can do personally to make sure your journey with PrEP is healthy and provides you with maximum benefit, there are a few things your healthcare provider will want to do as well.
Firstly, you and your provider should continue to have ongoing discussions about your sexual health – particularly when your sexual health circumstances change (i.e. you enter or exit a monogamous sexual relationship, the HIV status of your sexual partner(s) changes, or your use of other HIV prevention methods increase or decrease). This is important to make sure that PrEP is still an HIV prevention option that makes sense for you.
Additionally, there are other sexually transmitted and blood borne infections (STBBIs) that can negatively impact your health besides HIV – some of which, like syphilis, can even lead to severe neurological impairment or death if undiagnosed. By having ongoing conversations about your sexual health circumstances and HIV/STBBI prevention practices, your healthcare provider can ensure you have the knowledge and tools necessary to ensure optimal sexual health.
Besides ongoing sexual health counselling, your healthcare provider will run a series of tests on you when you start PrEP and at varying points while on PrEP (30 days after you start, every three months, and yearly) to make sure you remain HIV-negative, STI free, and that the medication isn’t having any negative effects on your health. These tests should also be accompanied by clinical assessments to ensure proper adherence and determining whether other things in your life may be increasing your HIV risk. Visit Appendix F of the Albertan PrEP Guidelines to learn more about these.
In many cases, your healthcare provider will require you to complete recommended screenings before renewing your prescription. Although this might seem like an inconvenience, it is a small price to pay to access PrEP and maintain optimal sexual health! For a list of recommended screenings and related frequencies, click here.
There are certain situations which may require you to stop taking PrEP; such as testing positive for HIV or experiencing a significant decline in renal function. Other scenarios, like no longer meeting eligibility criteria or having trouble taking your medication as prescribed may also may also be a reason to electively discontinue taking PrEP. Regardless of the reason, this decision should be made with your healthcare provider to ensure that it is the best option.
Before stopping PrEP, make sure you consider a few things:
Before you stop PrEP, take some time to think about whether or not the circumstances related to deciding to stop taking PrEP will remain static for a while, or if they could change in a month or two leading you to consider starting PrEP again. If things are prone to fast change, perhaps wait a little while before making a decision to stop.
If you haven’t made the decision to stop PrEP in consultation with a healthcare provider, you should make sure you speak with your PrEP prescriber before choosing to stop. They could support you through that decision-making process and if you do decide to stop taking PrEP they can help you determine other HIV prevention strategies for moving forward.
The Albertan PrEP Guidelines recommend continuing PrEP for up to 28 days after your last potential exposure to HIV, as well as follow-up HIV testing up to 8 weeks after stop taking your medication.
PrEP isn’t for everybody. Some people aren’t great candidates for PrEP to begin with. Some people might only benefit from PrEP for a short period of their life, stopping when circumstances change. And others would likely benefit from PrEP for a longer period – perhaps for their entire life. There’s nothing wrong with reviewing your sexual health practices and determining that what worked for you a month or year ago concerning HIV prevention is no longer the best option for you today. Just make sure that before stopping PrEP you take some time to look at other HIV prevention options to use in PrEP’s absence. To learn more about HIV prevention, check out our full website here.
Intermittent PrEP Use: The periodic use of PrEP both before and after a sexual encounter as opposed to continuous usage. This differs from the once/daily method in that PrEP use can be planned around a sexual encounter, and doesn’t need to be taken on a strict, daily regimen to get the protective benefits.
Adherence: Adherence refers to how often a medication is actually taken in comparison to how often it should be taken. For example if a medication is prescribed to be taken once a day for two weeks and you took one pill every day for 14 days, you would have perfect adherence. However, if you took the pill every other day or couple of days then you would have poor adherence.
STBBIs: Stands for Sexually Transmitted and Blood Bourne infections. This is a catch-all terms that encompasses all types of infections (both bacterial and viral) that can be transmitted through either sexual intercourse, or exposure to infected blood/blood products.