Pre-Exposure Prophylaxis (PrEP)

What is Pre-Exposure Prophylaxis (PrEP)?

 

Pre-Exposure Prophylaxis (PrEP) is any substance or medication taken to prevent the contraction of a disease; and example of this is PrEP used for the prevention of malaria.  This method has been explored in recent years as a possible addition to the preventative measures taken in regards HIV infection.  When used for this purpose, antiretroviral medication is taken orally (pill form) on a daily basis in an attempt to lower the chances of contracting HIV.

 

Current Research

 

There are two antiretroviral drugs at the forefront of this preventative research:

1. Tenofovir Disoproxil Fumarate (brand name Viread)
2. Emtricitabine

 

Tenofovir used in combination with Emtricitabine is marketed under the brand name Truvada which is taken daily as an oral preventative drug.  Tenofovir was licensed by the FDA as an HIV treatment for adults in October 2001, as was the Truvada combination pill as an HIV treatment in August 2004.[1] 

 

Pre-Exposure Prophylaxis Initiative (iPrEx) was a clinical trial undertaken to determine the effectiveness and safety of the combination drug Truvada used for HIV prevention.  This study began on June 18, 2007 in Lima, and in November of 2010 the National Institutes of Health announced the trial results.  This was not the first or the only PrEP trial taking place; however it was the first large efficacy study to evaluate the use of PrEP that specifically targeted men who have sex with men (MSM).  The iPrEx trial targeted this group because studies have shown that MSM are at a much greater risk of contracting HIV than the general population.[2] 

 

The study showed that once daily use of the combination drug (tenofovir plus emtricitabine) Truvada, provided an average 44% additional protection against the contraction of HIV to MSM and transgendered women who have sex with men.  Consistent use of the drug returned even more promising numbers: in those participants who used the drug on 90% or more days, HIV risk was reduced by 73%, compared to those who used it less than 90% and only returned a 21% prevention rate.[3]

 

A New Tool in the Prevention Tool Box

 

To date, PrEP has only been shown to reduce HIV infection among men who have sex with men; no data regarding its effectiveness amongst heterosexuals and injection drug users has been produced yet. 

 

While daily use of the Truvada pill has shown promising results in prevention against HIV infection, this was only in conjunction with other preventative measures including condom use, counseling, and management of other sexually transmitted diseases. 

 

Even though PrEP has proven effective as another tool in the prevention of HIV, it should never be used as a first line of defense against infection.  Consistent use of condoms, reduction of the number of sexual partners, and being aware of your partner's status in regards to HIV, are all measure that should be taken to help reduce ones risk of contracting the virus.

 

For more information on PrEP

 

Centers for Disease Control (CDC)

1-800-232-4636

1600 Clifton Rd.

Atlanta, GA. 30333

www.cdc.gov

 

CDC′s Mission is to collaborate to create the expertise, information, and tools that people and communities need to protect their health - through health promotion, prevention of disease, injury and disability, and preparedness for new health threats.

 

Global iPrEx

1650 Owens Street, 5^th floor

San Francisco, CA. 94158

www.globaliprex.com

iPrEx, or Pre-Exposure Prophylaxis Initiative is a clinical trial aimed at determining whether two antiretroviral (ARV) medications used to treat HIV/AIDS help prevent HIV acquisition in HIV-uninfected people at high risk of HIV infection.