The Bush administration announced a major new initiative Thursday that would give the Food and Drug Administration (FDA) unprecedented access to information on drug side effects from Medicare’s massive prescription database.

The so-called Sentinel System is designed to enable the FDA to detect unexpected side effects from FDA-approved prescription drugs much more quickly and accurately than ever before, Bush administration officials said.

In 30 days, the FDA will have access for the first time to Medicare claims data housed at the Centers for Medicare and Medicaid Services (CMS). The FDA will be able to use these data to determine links between drugs and side effects, also called “adverse events.”

The FDA will be able to investigate whether a specific drug is associated with a specific side effect among a much greater number of patients than under the current, voluntary side effects reporting system, which will remain in place.

“Before Sentinel, tracking drug safety was like looking at the stars in your backyard with the naked eye,” Leavitt said. “After Sentinel, it’s like giving you the strongest telescope on the market.”

Being able to detect when a drug is causing serious and unexpected side effects could save lives by allowing the FDA to move more swiftly to warn patients and doctors or even demand a drug be pulled off the market.

The FDA and the drug industry have been sharply criticized for not being aggressive enough in responding to warnings about serious side effects, such as in the case of the painkiller Vioxx, which was yanked off the market when evidence mounted linking it to severe and even fatal cardiac side effects.

For now, the FDA will have access only to Medicare data. As the program is implemented, the agency will be able to tap into information from other federal agencies, such as the Department of Veterans Affairs and the Department of Defense, and from private health insurance companies. As electronic prescriptions and electronic medical records proliferate, the available information will grow further, Leavitt said.

This information will provide the FDA with a wealth of data on what drugs are being prescribed and what medical conditions those patients have. FDA officials can analyze that information to determine whether a side effect is associated with a medicine. The information contained in the databases is stripped of anything that could identify the patients, the administration officials stressed.

The FDA must approve all drugs before they can be prescribed based on clinical trials conducted by researchers. Although those trials test medicines on thousands of people, a full understanding of drugs’ side effects cannot be achieved until many more thousands or millions of people are using the medicine on a regular basis in the marketplace.

FDA Commissioner Andrew von Eschenbach said the new system will allow the agency to find out about side effects and step in much more quickly.

“This is a significant step forward in our ability to intervene earlier and with much greater accuracy and precision to determine the adverse events and taking the appropriate steps to further protect the American people,” he said.

Currently, the FDA relies on voluntary reporting of side effects by doctors and other medical providers to its MedWatch database.

CMS published a regulation Thursday to allow the FDA, other federal and state agencies, researchers and beneficiaries to access Medicare’s drug claims data.

Acting CMS Administrator Kerry Weems said the program also would save money by lowering the number of side effects that lead to costly treatments. “The reduction of adverse drug events will not only promote the healthcare of our beneficiaries but is a key step in reducing unnecessary costs to the Medicare trust fund,” Weems said.