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For Providers

PrEP and PEP are two pharmacological options that you can offer and prescribe to your HIV-negative patients.

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Key Facts


PrEP and PEP are two different methods to prevent HIV


PrEP is FDA approved for individuals 15 years old and older


PEP should be prescribed immediately, within 72 hours of their possible exposure to HIV


Transition patients from PEP to PrEP if they remain at risk for HIV infection


There are medication payments programs available to patients


There is a generic form of Truvada available but not for Descovy

Information for Providers

Who should take PrEP?

PrEP has been shown to help reduce HIV infection risk in multiple clinical trials. The iPrEx trial showed that PrEP reduces the risk of HIV infection among gay and bisexual men and transgender women. Two large trials, Partners PrEP and TDF2, showed that PrEP also reduces the risk of HIV infection among heterosexual men and women. The Bangkok Tenofovir Study demonstrated that PrEP works for people who inject drugs.

Medications approved for PrEP

There are now two approved medications for Pre-exposure Prophylaxis (PrEP): Truvada (emtricitabine and tenofovir diproxil fumarate) and Descovy (emtricitabine and tenofovir alafenamide).  Truvada is also available in a generic form known as Teva.

Truvada is a combination of two drugs: 300mg of Viread (tenofovir DF) and 200mg of Emtriva (FTC). In July 2012, it was approved as Pre-exposure Prophylaxis (PrEP) and used to prevent HIV among those at high risk for the infection, in conjunction with additional safer-sex behaviors. It was first approved by the U.S. Food and Drug Administration (FDA) as a component of therapy for people living with HIV in August 2004.

What are the side effects of Truvada?

  • Truvada (TDF/FTC) is generally well-tolerated.
  • Rare, but severe adverse reactions can include: Lactic acidosis, severe liver problems, and exacerbation of hepatitis B for those with HBV infection who suddenly stop TDF/FTC. Consider using an anti-HBV if stopping treatment.
  • Common adverse effects include: Headache, diarrhea, flatulence and nausea.
  • Long-term effects of TDF/FTC include renal insufficiency and decreased bone mineral density.

Descovy (TDF/TAF) is a combination of two drugs: 200mg of emtricitabine and 25mg of tenofovir alafenimide. On October 3, 2019, the FDA approved as PrEP to prevent HIV-negative persons.  Descovy was studied in the DISCOVER trial where is showed non-inferiority to daily Truvada.  Descovy had better results on bone mineral density and renal safety compared to Truvada.

How effective is PrEP?


  • The first randomized controlled trial producing statistically meaningful results of PrEP was announced on November 23, 2010. The iPrEx (Pre-exposure Prophylaxis Initiative) trial found that the HIV infection rate in HIV-negative gay men who were given a daily pill containing two HIV drugs was reduced by 44%, compared with men given a placebo. The efficacy in subjects who, by self-report and pill count, took the drugs more than 90% of the time was 73%.
  • The Partners Demonstration Project among discordant heterosexual couples (where one partner is HIV-positive and one is not) in Kenya and Uganda showed that a program that delivers both PrEP for HIV-negative partners and/or antiretroviral treatment (ART) for HIV-positive partners reduced the risk of HIV infection by 96%. These results highlight the potential impact of combining PrEP and ARV treatment to slow the HIV epidemic.
  • The PROUD Study among high-risk men who have sex with men (MSM) in the UK showed that daily oral PrEP reduced the risk of HIV infection by 86% when delivered in existing public health clinics.
  • The French study, IPERGAY, was the first to examine the efficacy of “event-driven” PrEP. In this case, a three-day dosing strategy involving four pills around the time of sex. This was among high-risk MSM who reported frequent sex. Overall, PrEP reduced the risk of HIV infection by 86% in the trial. Based on reported pill use by men in the trial, the regimen that most participants took amounted to at least four doses a week. Previous studies of daily oral PrEP have shown that this may be enough to be protective. However, it is not clear how well the event-driven regimen would work for men who have less frequent sex than the men in the trial. PrEP “on-demand” is not FDA approved at present.


Guidelines for prescribing PrEP

Medications approved for PEP

Guidelines for prescribing PEP non-occupational post exposure prophylaxis.

A guide to discussing sexual health with MSM