Centers for Disease Control and Prevention defines pre-exposure prophylaxis (or PrEP) as follows: “[When] people at very high risk for HIV take HIV medicines daily to lower their chances of getting infected.”
“Prophylaxis” refers to any treatment meant to prevent an infection from happening.
AIDS.gov states that PrEP is for people who are at ongoing risk of HIV infection. Ongoing risk means people who have partners who are at a high risk of being HIV positive or are HIV positive. Those who are at ongoing risk are people “who have injected drugs in the past 6 months and have shared needles or works or been in drug treatment in the past 6 months,” those having unprotected sex with at-risk partners, or those who have many partners or partners with many partners.
Post-exposure prophylaxis (PEP), not PrEP, is made for singular-risk events that include “sex without a condom, needle-sharing injection drug use, or sexual assault.” The site also states that the drug works better when combined with other forms of prevention such as getting tested for HIV and using protection.
The medicine comes in pill form and is recommended to be taken daily. And the San Francisco AIDS foundation says that not taking the daily recommended dose can highly increase the risk of the medicine not working.
The brand name of the only FDA approved PreP medication available on the U.S. market right now is TRUVADA. The TRUVADA website says that the medicine is a combination of two different drugs, Emtriva (also called emtricitabine or FTC) and Viread (also called tenofovir disoproxil fumarate or TDF). These two medicines work together to prevent HIV from taking hold in the body. There are also a number of other PrEP medicines still in development.
The TRUVADA website states, “[Common] side effects [are] stomach-area (abdomen) pain, headache, and decreased weight.” While these are the generally stated short-term side effects, there are also reports that the medicines contained in TRUVADA have led to long-term negative side effects such as “compromising kidneys or depleting bone mineral.”
However, The Center for AIDS Information and Advocacy has issued research-based statements explaining statistics in the category cannot fully claim whether or not it actually is the drugs found in TRUVADA that cause these long-term symptoms.
This is because people who are at a higher risk of HIV and are therefore taking PrEP are also usually people who because of their particular socio-economic status, racial background, or sexual or preference for instance, are at risk for a higher percentage of other conditions that can cause the same long-term effects, such as sexually transmitted diseases. This research then concludes that TRUVADA drugs are not responsible, perhaps completely or maybe at all, for those negative long-term side effects.