Last last year researchers announced some success in preventing HIV among gay men who were taking a daily dose of the HIV medication Truvada. The concept of warding off infection by pre-dosing with a medication is known as pre-exposure prophylaxis (PrEP.) But alarmed by the prospect for abuse, yesterday the CDC issued some interim PReP guidance as studies continue.
CDC says it wanted to fend off improper use of pre-exposure prophylaxis (or, more catchily, PrEP) as it and other agencies work on more detailed guidelines, which will take “several months.” It says that the drug should only be used in men who have sex with men, since studies in other high-risk groups such as IV drug users are still underway. And it should be used only in high-risk men (with multiple partners or partners from an area with a high prevalence of HIV infection), who are most likely to benefit. Also, the drug isn’t the equivalent of the morning-after pill for HIV; it’s meant to be taken daily. “Support for adherence to the prescribed medication regimen must be a routine component” of PrEP, the CDC says. (In the study, the risk of HIV infection was reduced just 21% in men whose adherence was less than 90%, compared to a 73% lower risk of infection for those with adherence of 90% or better.) And other preventive measures, such as condom use, should continue to be taken.
The wholesale cost of Truvada in the United States is $1000 for a month’s supply, a cost unlikely to be covered by insurance when the drug is used as a preventive. In some countries, Truvada costs as little as $12/month.