By David Brown
Thursday, June 17, 2010; A19

The Food and Drug Administration this week began posting online the results of safety evaluations of recently approved drugs and vaccines.

The action follows a law enacted in 2007 that requires the agency to provide more safety information to consumers and health professionals. The evaluations must be conducted 18 months after a new drug comes on the market.

Rare and sometimes serious side effects are often discovered only when a drug is used by a much larger and more varied group of patients than exposed to it in clinical trials leading to its approval.

The "post-market" analysis draws on many sources of information -- spontaneous reports of problems from doctors and patients, new studies, foreign experience with the drug, pharmaceutical company data and information from prescription data bases.

The data won't be posted for every product FDA approves, as many products are similar to many other drugs in use. Instead, the information will be about drugs with novel chemical structures ("new molecular entities"), new biological substances (such as vaccines and monoclonal antibodies), and old drugs approved for new uses or new target populations.

FDA put up synopses of 26 such reviews Tuesday at http://www.fda.gov. It will post new ones quarterly, for a total of about 100 a year, said Robert M. Boucher, a physician in the agency's pharmacovigilance division. However, it won't post any for drugs approved before Sept. 27, 2007.