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From NPR News, this is ALL THINGS CONSIDERED. I'm Robert Siegel.
AUDIE CORNISH, HOST:
And I'm Audie Cornish. Today, the Food and Drug Administration approved a pill that can prevent HIV. It's the first medication to do that. Studies show the pill can drastically reduce the risk of infection, but the FDA stresses that people have to take it faithfully every day and keep practicing safe sex.
NPR's Richard Knox explains.
RICHARD KNOX, BYLINE: Scientists call it PREP. That stands for pre-exposure prophylaxis. That just means that people take the pill before they're exposed to the AIDS virus in order to prevent infection with HIV. A number of studies all over the world have shown that it can work. It can cut the risk of infection anywhere from 44 to 90 percent. We'll get back to why there's such a wide range in a minute.
The pill is called Truvada. It's a combination of two antiviral drugs that have been widely used for several years to treat people already infected with HIV. In approving Truvada for PREP, officials say they hope the pill can prevent some of the 50,000 new infections that occur in this country every year, but Dr. Debra Birnkrant of the FDA says it's not clear what the impact will be.
DR. DEBRA BIRNKRANT: I don't think we know exactly how many individuals will be using Truvada for PREP.
KNOX: The FDA is stressing that people taking the pill shouldn't feel they're safe.
BIRNKRANT: Truvada alone should not be used to prevent HIV infection.
KNOX: They should continue to use condoms and limit the number of sexual partners they have. One big worry is whether people taking Truvada will relax other safe sex precautions.
BIRNKRANT: We are concerned about increased risks, however, the trials did not bear that out and the goal is that the health care providers, when they have their extensive conversations with individuals, they will go through key messages.
KNOX: Those messages are only partly about condoms and promiscuity. There are other important issues. Nobody should start taking Truvada for PREP before making sure he or she is not already infected with HIV. That's because this pill by itself is not effective in fighting an infection once it's begun. That requires at least one additional antiviral drug. Without it, the virus may become more difficult to treat.
People taking Truvada for PREP also need to get an HIV test every three months and people with kidney problems or Hepatitis B should not be using Truvada. But the most important message is you've got to take the pill every single day. People who did that in studies had a high level of protection, says Boston AIDS researcher Kenneth Mayer.
KENNETH MAYER: The people assigned to the PREP group who were consistently taking their medication had a benefit of 90 percent that they were that much less likely to become HIV infected compared to people assigned to the placebo group.
KNOX: But studies also showed that most people weren't faithful about taking the pill and, when they didn't, their risk was reduced much less to 75 percent, 44 percent or zero. Mayer says achieving perfect adherence is unrealistic.
MAYER: Nobody thinks that that's necessarily obtainable.
KNOX: So doctors who prescribe PREP need to have frank talks with patients about their ability to stick to the regimen.
MAYER: It's certainly not something that we want to just distribute in the drinking water or just distribute willy-nilly, because people really have to understand the need for a certain regimentation in taking the medication.
KNOX: There's another big unknown. In this country, Truvada costs around $13,000 a year. It's not yet clear how many insurers will pay for that.
Richard Knox, NPR News.
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