U.S. health officials said Thursday that doctors should consider giving an AIDS prevention pill to women and heterosexual men who are at high risk for getting the virus.

The U.S. government previously advised doctors to give the once-a-day pill Truvada to high-risk gay and bisexual men only. However, more than a quarter of new HIV cases each year are heterosexuals, according to the U.S. Centers for Disease Control and Prevention.

Truvada has been on the market in the U.S. since 2004 to treat people who already have the AIDS virus. (Jeff Chiu/Associated Press)

"That's not a portion of the epidemic we want to ignore," said Dr. Dawn Smith, the CDC physician who was lead author of the new guidance.

Truvada has been on the market since 2004 to treat people who already have the AIDS virus. But after studies showed it could help prevent infection among gay and bisexual men, U.S. health officials last year said doctors could prescribe it as a preventive for men at high risk.

Since then, studies have found it also can prevent the virus in women and heterosexual men.

Last month, the U.S. Food and Drug Administration formally approved the sale of Truvada as a preventive measure for healthy people at high risk of getting HIV.

The CDC is not recommending the pill for all sexually active heterosexuals. And even among couples where one person has HIV, regular condom use generally is effective protection. There are an estimated 140,000 heterosexual couples in which one person is infected with the AIDS virus.

But the pill would be a good option for a couple that wanted to have a baby, Smith said, describing one possible scenario.

The drug's manufacturer, Gilead Sciences Inc., said this week it's difficult to break down what portion of Truvada sales have been for prevention.

When used as a preventive, the pill is taken once a day. It costs between $6,000 and $12,000 US a year, although some private insurers and Medicaid programs have been covering it, Smith said.

Treating gonorrhea

The CDC also had new advice about treatment for another sexually transmitted disease — gonorrhea.

Health officials are recommending that whenever possible, doctors stop using an antibiotic commonly used to treat it. They're worried about signs that gonorrhea is becoming resistant to it.

The antibiotic is a pill called cefixime, and it belongs to the last remaining class of drugs effective for gonorrhea. The one remaining recommended drug is a shot called ceftriaxone.

Cefixime is still effective in most cases. But officials feel they can't take a chance that the resistance they've begun to see will continue. If it does, that could also strengthen gonorrhea to resist ceftriaxone, they believe.

"This change is a pre-emptive strike" to preserve the last treatment option, said Dr. Gail Bolan, who oversees the CDC's sexually transmitted diseases prevention programs.

Gonorrhea, once known as the clap, was once the scourge of soldiers and sailors. It was tamed by penicillin, but the germ is now resistant to that and to several drugs that followed.