The government is warning manufacturers of drugs used in the treatment of AIDS not to imply too much in their advertising.

The Food and Drug Administration acted Friday after it determined that some advertisements, particularly on the West Coast, seemed to imply that with modern treatment people did not need to worry about AIDS.

An ad might, for example, show two people enjoying outdoor recreation, with the caption that they both tested positive for HIV, the virus that causes AIDS, but were still enjoying life.

The agency's Division of Drug Marketing, Advertising and Communications said it reviewed these direct to consumer ads and concluded that "many do not adequately convey that these drugs neither cure HIV infection not reduce its transmission."

The advertising in question needs to be changed within 90 days, FDA said, noting that promoting the drugs without displaying their limitations, and using images not representative of HIV patients, is in violation of the federal Food and Drug Act.

In San Francisco, Board of Supervisors President Tom Ammiano and activists throughout the city's large gay community attended a meeting this month to discuss banning the ads if they were not toned down.

"This problem has been going on with several other diseases and several other drugs — it took AIDS to finally make the FDA act," said Jeff Getty, an activist from Survive AIDS, who was infected with the disease 20 years ago. "This is a weight taken off my shoulders."

A survey by the city's Public Health Department recently found 61 percent of 422 gay and straight men say AIDS drug ads covering billboards, magazine pages and other venues affect decisions on whether to have unsafe sex.

The study follows a report that found the rate of HIV infection has more than doubled among San Francisco's gay men in the last four years.

Overall, AIDS deaths have declined sharply in the last few years as the combination of drugs used to treat the disease has improved. But treatment can be costly and while it extends the life of the patients it doesn't cure the disease. In addition most of the drugs need to be taken in combination with other drugs, something the ads didn't always make clear.

"Although today's treatment regimens have transformed HIV infection to a chronic disease in many patients, HIV infection is still associated with significant" illness and death, the letter said.

It noted that people on therapy can still pass the disease on to others, so precautions must still be taken.

The letter from Thomas Abrams, director of the division of marketing, advertising and communications, also pointed out that not all people respond to the drugs, and it said some ads minimize side effects of the drugs, which can include redistribution of body fat and facial wasting.

The FDA did not single out any particular drug maker, saying it sent the advisory to all companies that make drugs to treat AIDS. It asked them to reply by May 18, listing promotional materials to be changed and stating when that would be done.

Companies making drugs for the treatment of AIDS include Abbott Laboratories, Agouron Pharmaceuticals, Boehringer Ingelheim Corp., Bristol-Myers Squibb, DuPont Pharmaceuticals, GlaxoSmithKline, Hoffmann-LaRoche Inc. and Merck & Co.