Myth or Truth: Will PrEP Create Drug Resistance?

Editor's Note: There are, unfortunately, many myths going around about pre-exposure prophylaxis, or PrEP -- the use of an antiretroviral drug by HIV-negative people to prevent them from being infected with HIV during sex. This month we'll look at one myth per day and offer evidence why it's not true.

Myth: PrEP will create a drug-resistant HIV.

Truth: The iPrEx study, a large international research project on the use of Truvada for PrEP, found a low risk of drug resistance -- in fact, the only cases of resistance developing were in people who had unrecognized acute HIV infection. This drives home the importance of being tested for HIV regularly while on PrEP. While it is also important to take your PrEP medication every day as directed, study participants who missed doses, resulting in what study authors called "periods of low drug exposure," did not have a greater risk of developing drug resistance. Drug resistance is a concern for people with HIV, but not one associated with PrEP. A recent study found that 16 percent of HIV strains in newly infected people in the U.S. metropolitan areas are resistant to one or more HIV drugs. Resistance generally develops when people with HIV don't take their drugs regularly, therefore allowing the virus to multiply and mutate into a drug-resistant strain. Truvada is used to treat HIV as well as prevent it, so you don't want to develop resistance to it -- but the key, if you're taking it for PrEP, is to get your regular HIV tests to make sure you're remaining negative.