WASHINGTON — The Senate passed a bill on Wednesday that would give the Food and Drug Administration new power to police drug safety.

The bill calls for a fundamental change in the philosophy and operations of the drug agency, requiring it to focus on the entire life cycle of a drug — not just the years before its approval — as well as the experience of patients who later take it.

Under the bill, the government would establish a surveillance system to track the adverse effects of prescription drugs. Scientists would analyze data on tens of millions of patients, looking for signals that particular drugs pose serious risks.

In passing the measure by a 93-1 vote, the Senate sent a clear signal that it wanted stronger action by the agency to protect public health. Senators said the bill responded to a widespread loss of confidence in the ability of the agency to protect consumers against the dangers of drugs like Vioxx, a popular painkiller withdrawn from the market in 2004.

The bill, which would carry out many recommendations from the National Academy of Sciences, is likely to become law. It appears broadly acceptable to the House, which is working on its own version of the bill, and is unlikely to be vetoed by President Bush.

The administration has not actively opposed the measure, although it says the agency already has all the regulatory authority it needs. Within the agency, officials have been divided about whether they have the enough power.

The bill is widely seen as "must-pass" legislation because it renews authority for the government to collect fees from drug companies to speed reviews of their products. Without action by Congress, the authority expires on Sept. 30.

Billy Tauzin, president of the Pharmaceutical Research and Manufacturers of America, the main trade group for manufacturers of brand name drugs, applauded the passage, of the bill, saying it "will preserve and even strengthen the FDA's ability to do its job."

Drug companies would be required to do follow-up studies on certain medicines or risk fines. The FDA could require label changes for drugs.

An active surveillance program would replace the largely passive way the FDA now learns of potential problems with drugs on the market. It calls for the mining of federal and private databases that log side effects in tens of thousands of patients.