From the Guidelines
Pre-exposure prophylaxis (PrEP) is recommended for HIV prevention in individuals engaging in anal sex who are at risk of HIV acquisition, with the primary medication regimen being daily oral Truvada (a combination of emtricitabine 200mg and tenofovir disoproxil fumarate 300mg) or Descovy (emtricitabine 200mg and tenofovir alafenamide 25mg), as supported by the 2016 recommendations of the International Antiviral Society-USA panel 1. The use of PrEP has been shown to be effective in reducing the risk of HIV acquisition, with a 44% reduction in HIV acquisition observed in the iPrEx study 1.
- The iPrEx study demonstrated that daily oral TDF/FTC taken as PrEP is safe and partially effective in reducing HIV acquisition among men who have sex with men (MSM) when provided with regular monitoring of HIV status and ongoing risk-reduction and PrEP medication adherence counseling.
- The 2016 recommendations of the International Antiviral Society-USA panel suggest that daily TDF/emtricitabine with high adherence is highly effective for HIV prevention and is the recommended regimen 1. Some key points to consider when prescribing PrEP include:
- PrEP should be initiated after confirming HIV-negative status and requires ongoing monitoring every 3 months for HIV testing, STI screening, and kidney function assessment.
- PrEP works by blocking HIV replication in the body if exposure occurs, preventing the virus from establishing infection.
- It's essential to note that PrEP does not protect against other sexually transmitted infections, so condom use is still recommended.
- Additionally, post-exposure prophylaxis (PEP) with a 28-day course of antiretroviral medications should be considered within 72 hours if potential HIV exposure has already occurred, as recommended by the U.S. Department of Health and Human Services 1.
From the Research
HIV Prophylaxis for Anal Sex
The recommended Human Immunodeficiency Virus (HIV) prophylaxis for individuals engaging in anal sex is pre-exposure prophylaxis (PrEP) with a fixed-dose combination of emtricitabine and tenofovir disoproxil fumarate or tenofovir alafenamide 2, 3.
Types of PrEP
There are two main types of PrEP:
- Daily PrEP: involves taking a pill every day to prevent HIV infection 4
- On-demand PrEP: involves taking a pill before and after sex to prevent HIV infection, following specific guidelines such as the IPERGAY dosing recommendation 4
Efficacy of PrEP
Studies have shown that PrEP is highly effective in preventing HIV infection when taken as prescribed 2, 3, 4. The efficacy of PrEP is correlated with levels of adherence, with higher adherence resulting in greater efficacy 3.
Factors Associated with PrEP Use
Sociodemographic characteristics such as age, education level, and insurance status are associated with PrEP use 5. Men who have sex with men (MSM) and engage in condomless anal sex are more likely to use PrEP 5.
Challenges and Future Opportunities
Despite the efficacy of PrEP, there are several challenges to its implementation, including low awareness and utilization, uncertainty about adherence, limited data on long-term use, high costs, and stigma associated with PrEP use 6. Future opportunities include the development of innovative pharmacologic chemoprophylactic approaches, such as less-than-daily oral dosing regimens and long-acting injectable medications, to improve adherence and reduce pill burdens 6.
Key Findings
- PrEP with emtricitabine and tenofovir disoproxil fumarate or tenofovir alafenamide is effective in preventing HIV infection 2, 3
- Daily and on-demand PrEP are both effective in preventing HIV infection 4
- Adherence to PrEP is crucial for its efficacy 3
- Sociodemographic characteristics and behavioral factors are associated with PrEP use 5
- Challenges to PrEP implementation include low awareness, uncertainty about adherence, and stigma associated with PrEP use 6