New Medications Pose Unknown Dangers

Approximately 20 percent of new drugs pose major health risks that are not recognized at the time they enter the market, according to a review published in today's JAMA. The authors, from Harvard University and Public Citizen, investigated the 548 medications that were approved from 1975 to 1999 and found that 8.2 percent acquired new "black box" warnings—indicating serious risks—and 2.9 percent were withdrawn. Statistical risk of adverse drug reactions over 25 years was 20 percent.