NEW YORK — Federal health officials recommended Wednesday that hundreds of thousands of Americans at risk for AIDS take a daily pill that has been shown to prevent infection with the virus that causes it.
If broadly followed, the advice could transform AIDS prevention in the United States — from reliance on condoms, which are effective, but unpopular with many men — to a regimen that relies on an antiretroviral drug.
It would mean a fiftyfold increase in the number of prescriptions for the drug, Truvada — to 500,000 a year from fewer than 10,000. The drug costs $13,000 a year, and most insurers already cover it.
The guidelines tell doctors to consider the drug regimen, called PrEP, for pre-exposure prophylaxis, for gay men who have sex without condoms; heterosexuals with high-risk partners, such as drug injectors or male bisexuals who have unprotected sex; patients who regularly have sex with anyone they know is infected; and anyone who shares needles or injects drugs.
Officials at the Centers for Disease Control and Prevention have long been frustrated that the number of HIV infections in the United States has barely changed in a decade, stubbornly holding at 50,000 a year, despite 30 years of official advice to rely on condoms to block transmission.
Although there is no guarantee that gay men will adopt PrEP, federal officials say something must be done because condom use is going down. In a recent CDC survey, the number of gay men admitting to recent, unprotected sex rose nearly 20 percent from 2005 to 2011.
Nevertheless, advocates for PrEP were elated at Wednesday’s announcement.
“This is wonderful,” said Damon L. Jacobs, a therapist who has been on the regimen since 2011 and runs a Facebook page promoting it. “When an institution like the CDC makes a statement, it makes a profound difference to the doctors who are ambivalent.”
Dr. Jonathan Mermin, director of the CDC’s national center for AIDS and other sexually transmitted diseases, said the new guidelines should save many lives.
“On average, it takes a decade for a scientific breakthrough to be adopted,” he said. “We hope we can shorten that time frame and increase people’s survival.”
While many drugs could, in theory, be used for PrEP, the only pill approved for that purpose by the Food and Drug Administration is Truvada, made by Gilead Sciences.
Truvada, a mix of tenofovir and emtricitabine, is considered relatively safe, with few side effects. Generic versions are made in India, and the drug has become the backbone of AIDS treatment in poor countries. Common side effects include headache, stomach pain, and weight loss. Rare but serious side effects include liver and kidney damage.
Since 2010, three studies of Truvada have shown that, when taken daily, it can vastly reduce the chances of infection. That held true for gay men, heterosexual couples, and drug injectors. In the study of gay men, men whose blood tests showed they had taken their pill every day were 99 percent protected.
The new guidelines say patients should have an HIV test before starting the regimen to make sure they are not already infected. (Prophylaxis involves doses of two drugs, but anyone with the disease should be on triple therapy.) Patients should be retested every three months to be sure they are still HIV-negative, are not developing side effects, and have not caught any other sexually transmitted diseases.
While many AIDS specialists endorse PrEP, it has not caught on among doctors. A survey of 1,175 infectious disease specialists in the United States and Canada published in December showed that 74 percent supported PrEP, but only 9 percent had actually prescribed it.
“There’s a lot of inertia among doctors — and a strong statement from the CDC will be pretty valuable for overcoming that,” said Dr. Demetre C. Daskalakis, an AIDS specialist at Mount Sinai Hospital in New York.
Also, PrEP has not caught on among gay men, who are by far the largest risk group.
Gilead has tried to track how many Truvada prescriptions are for PrEP, rather than AIDS treatment. As of September, it knew of only 2,319, of whom 49 percent were women.
Advocates see several reasons there has been little clamor for PrEP. First, while many doctors prescribe statins as prophylaxis against heart attacks, for example, only AIDS specialists think about prescribing AIDS drugs as prophylaxis. But uninfected gay men have no reason to see AIDS specialists.
Another reason is that Gilead does not advertise Truvada for prophylaxis, though the FDA in 2012 approved that use. Nor does Gilead advertise Truvada for treatment, approved in 2004.
At risk for AIDS
Gay men who have sex
high-risk partners, such as drug injectors or male bisexuals who have unprotected sex
► Patients who regularly have sex with anyone they know is infected
► Anyone who shares needles or injects drugs