In an attempt to fend off criticism from doctors, consumer groups and Congress, Pfizer Inc. said it would revamp its consumer advertising for prescription drugs by better explaining risks and alternatives, submitting new television ads to the Food and Drug Administration for review and showing them to doctors at least six months before they air.

Pfizer made its announcement less than two weeks after the industry's main trade group announced a set of "guiding principles" that recommended some of the same measures. Earlier this year, a smaller rival, Bristol-Myers Squibb Co., said it would wait a year after FDA approval of a drug before launching consumer ads.

J. Patrick Kelly, president of Pfizer's U.S. operations, said the new policies are an attempt to put "some meat on the bones" of the trade group's guidelines, to improve consumer education about new drugs and to encourage consumers to talk to their doctors.

Senate Majority Leader Bill Frist (R-Tenn.), who has called on drugmakers to adopt a two-year moratorium on consumer ads, called the Pfizer move a "step in the right direction," but said "more needs to be done," according to a spokeswoman.

An industry critic dismissed both the Pfizer and the industry initiatives, saying they rely too much on voluntary compliance and self-policing and too little on enforcement by the FDA.

"It's another PR stunt," said Sidney M. Wolfe, director of Washington-based Public Citizen's Health Research Group. "The main purpose is to polish up the extremely tarnished image that Pfizer and the entire drug industry has right now."

Pfizer said it also will include language in both print and TV ads for its drugs noting that doctors may recommend alternative treatments, such as diet and exercise, and will research ways to better communicate risks in TV ads. The company also said it will air ads for anti-impotence drugs only on programs with 90 percent or more adult viewership.

The New York-based company said it will spend a "meaningful amount" on ads that create "disease awareness" without mentioning a specific drug. Kelly declined to disclose how much the company would spend but said it would be similar to the amount spent on a drug campaign. Pfizer last year spent $120 million on direct-to-consumer ads to support Lipitor, its anti-cholesterol drug, according to Nielsen Monitor-Plus, a unit of Nielsen Media Research.

Direct-to-consumer advertising has exploded since 1997, when the FDA relaxed a guideline that had required drugmakers to use essentially the same language in TV drug ads that appeared in the fine print of magazine and newspaper ads. The new guidelines require only that TV ads stress major health risks and benefits.

Last year, drugmakers spent $4.15 billion on consumer ads, compared with $850 million in 1998, according to Nielsen. Prescription-drug ads on TV have gone from unheard-of to ubiquitous and now include such memorable campaigns as AstraZeneca's "purple pill" (Nexium, for treating acid reflux disease) and Pfizer's "Gotta go" jingle to support Detrol, a bladder-control drug.

A survey this year by the Kaiser Family Foundation, a nonprofit research organization, found that 9 in 10 adults had seen or heard ads for prescription drugs. A fourth of those responding said they had talked to doctors about specific medications as a result of ads. Of those, 3 in 4 said say they received a prescription, either for the advertised drug or another, as a result of the visit.

Another Kaiser study, performed in 2003 with Harvard University and Massachusetts Institute of Technology, found that every dollar the industry spent on drug ads, both consumer and non-consumer, yielded sales of $4.20.

But opposition has developed in Congress and among consumer advocates, who blame the ad explosion for, among other things, driving up health care costs by spurring patients to demand expensive prescription medications they made not need. Doctors complained that patients were asking them about drugs before the doctors had heard of them.

Last fall, Pfizer pulled ads for its anti-impotence drug Viagra after criticism that the ads improperly implied that the drug bolstered the sex drive.

In a recent speech, Frist said consumer ads, while potentially valuable, may be driving excessive health-care spending. "Are these ads, which we know are costing billions, properly educating patients or just peddling expensive products?" he said.

The American Medical Association considered calling for a voluntary moratorium on the ads but voted instead to continue studying the issue.

Ads that implied Viagra boosted libido were pulled.