ATLANTA - Doctors should consider giving a daily AIDS drug to another high-risk group to help prevent infections - people who shoot heroin, methamphetamines or other injection drugs, U.S. health officials said Wednesday.
A similar recommendation is already in place for gay men and heterosexual couples at high risk of catching HIV, the virus that causes AIDS.
The latest advice was triggered by the results of a study done in Thailand that showed the AIDS drug tenofovir protected many drug users. Volunteers who took the daily pill were about 50 percent less likely to become infected than those given a dummy pill.
"This study completes the story" telling how HIV drugs can protect people at highest risk of infection, said Dr. Jonathan Mermin, director of AIDS prevention for the Centers for Disease Control and Prevention.
The research by the CDC and the Thailand government was published online Wednesday by the journal Lancet.
Based on the findings, the CDC recommended that doctors consider prescribing tenofovir to those who inject drugs. It blocks the virus from making copies and spreading through the body.
In the U.S., tenofovir is included in an AIDS drug called Truvada.
HIV infections in drug users account for about 1 in 10 new cases each year and the vast majority of infections in some places in Eastern Europe and Central Asia.
In the U.S., they represent about 1 in 13 new cases.
People who inject drugs can spread the AIDS virus to others through sharing tainted needles or sex.
How many people already take the drug in the U.S. to protect against infection isn't known; the CDC began recommending it for that purpose only in the last two years.