SAN FRANCISCO (KCBS) – A promising drug shown to decrease the likelihood of transmitting HIV should only be prescribed to men at high risk who are closely monitored by a doctor, federal health officials said Friday.

Research from UC San Francisco that shows Truvada lowered the risk of becoming infected with HIV by 44 percent focused on men who have sex with men, said Dr. Susan Bookbinder, director of HIV research at the San Francisco Department of Public Health.

“This was a groundbreaking study,” she said.

“It’s the first biomedical strategy in gay and bisexual men that was shown to reduce the risk of infection.”

KCBS’ Margie Shafer Reports:

The drug manufactured by Gilead Sciences in Foster City must be taken daily, typically by someone who is already HIV positive. The regime can cost as much as $12,000 a year.

The CDC guidelines call for testing before starting the drug, and then follow-up testing every two to three months.

Whether Truvada is as effective in women has yet to be fully studied, said Dr. Merv Silverman, who directed the city’s public health department during the early years of the AIDS crisis.

“Though I think it may work,” he said.

“But right now this has been shown to work only in homosexual couples, and so we’re not really sure how that will work in a heterosexual situation, how women will benefit from this.”

Silverman said prescribing Truvada freely to anyone who asks for it was not a good idea, since condoms remain essential for preventing the spread of HIV even in couples where one of the partners is on the drug.

“You don’t want to lose the impact of the counseling,” Silverman said, especially reinforcing advice about condoms.

“Your primary prevention technique is the proper use of condoms,” he said.

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