TUESDAY, April 17 (HealthDay News) -- A once-a-day pill to prevent HIV infection could significantly reduce the spread of the AIDS-causing virus, but would only be cost-effective if limited to men at very high risk for HIV infection, according to a new study.
Stanford University researchers created an economic model to analyze the use of the combination drug tenofovir-emtricitabine (brand name Truvada). A clinical trial found that the drug reduced a person's risk of HIV infection by an average of 44 percent when taken daily. In some people, the drug reduced the risk by 73 percent.
But the drug is expensive -- $26 a day, or $10,000 a year.
The economic model focused on men who have sex with men, a group that accounts for more than of the 56,000 new HIV infections a year in the United States, according to the U.S. Centers for Disease Control and Prevention.
The researchers found that giving the pill to all U.S. men who have sex with men would cost $495 billion over 20 years, compared to $85 billion if the pill was given only to gay men at particularly high risk for HIV infection -- those who have five or more sexual partners in a year.
Without the use of the anti-HIV pill, there would be more than 490,000 new HIV infections among gay men in the United States over the next 20 years. If 20 percent of men who have sex with men took the pill daily, there would be nearly 63,000 fewer infections over the next 20 years. If 20 percent of high-risk gay men took the pill, there would be 41,000 fewer infections over 20 years, the researchers said.
The study is in the April 17 issue of Annals of Internal Medicine.
Giving the pill to high-risk gay men represents good value, according to study first author Jessie Juusola, a Ph.D. candidate in management science and engineering in the School of Engineering at Stanford University.
"However, even though it provides good value, it is still very expensive," she said in a university news release. "In the current health-care climate, (these) costs may become prohibitive, especially given the other competing priorities for HIV resources, such as providing treatment for infected individuals."
Cost could be significantly reduced if the pill is found to be effective when used intermittently rather than daily. Clinical trials are under way to assess the drug's effectiveness when it is used less often than once a day.
The U.S. Centers for Disease Control and Prevention has more about HIV transmission.
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