Pre-exposure prophylaxis (in the case of HIV) is when antiretroviral medications are taken before a possible exposure to HIV in order to reduce the risk of infection. Results with PrEP are mixed and appear dependent on the specific population tested, level of adherence and use of additional prevention methods such as condoms and HIV education and counseling. When taken as prescribed, study results show PrEP to be effective. However, daily adherence is a major road block to decreasing the risk of HIV infection through PrEP. As such, prescription of PrEP should be highly monitored and scrutinized.
Who should use PrEP? – Research has shown mixed results dependent on the population tested.
- Men who have sex with men – The iPpEx study found a 44% reduction in risk in men who had sex with men who took Truvada.
- Heterosexual discordant couples – The Partners PrEP study followed 4747 couples in which one partner was HIV positive and the other was HIV negative. The negative partners were randomized to Truvada, TDF or placebo. Of the 82 partners infected, 17 were in the TDF arm, 13 in the Truvada arm and 52 in the plecebo arm. This equated to a 67% reduction with TDF and 75% with Truvada. Another study in heterosexuals called TDF2 found a 62% reduction with Truvada.
- Women – Results from the VOICE study which measured two potential prevention methods (PrEP and microbocide gel), showed that PrEP was not a viable option as protection against HIV for African women. The 5029 women study measured Truvada as PrEP, Tenofovir as PrEP and a Tenofovor based microbocide gel. Similar results were seen in the FEM-PrEP study. In this study of 2120 HIV negative women in South Africa and Tanzania, the rate of HIV infection in women on PrEP versus women receiving placebo were virtually the same (4.7% verses 5%).
- IV Drug Users – A study of 2,413 men and women who inject drugs in Thailand reported a 49% decrease in HIV infection with the use of Tenofovir.
What drugs are used as PrEP? – Truvada was approved for PrEP in the U.S. In July of 2012. Truvada is a combination of Tenofovir and Emtricitabine.
Side Effects – People taking Truvada for PrEP may experience side effects such as diarrhea, nausea and gut pain, as well as headache and weight loss. Kidney damage and a reduction in bone density have also been seen in some people, though it is reported that these adverse events reverse with discontinuation of Truvada. It is yet to be seen whether long term side effects occur.
How do I get PrEP? – PrEP should be prescribed by a doctor and not taken on your own under any circumstance.
You should not take PrEP if:
- You are unable to be tested regurally for HIV.
- You are unable to take PrEP daily as prescribed.
- You do not know your Hep B status.
- You have kidney problems.
- You do not know your HIV status.