By Laura Gilcrest, CBS MarketWatch
WASHINGTON (CBS.MW) - Medical experts said Friday that a government whistleblower was right to question the safety of five popularly prescribed drugs, and pointed to fundamental holes in the U.S. drug approval system.
The Food and Drug Administration has no authority to follow up on the safety of drugs once they are approved, leaving Americans vulnerable to unforeseen risks that show up only after the drugs are in widespread use, said Fernando Martinez, a professor at the University of Arizona Respiratory Sciences Center.
"Companies tell us what they want to tell us," said Martinez, a member of FDA's pulmonary-allergy drugs advisory committee.
Yet the most reliable data on drug safety is collected after drugs are cleared for the market, Martinez said. He said legislation to give the FDA more authority might solve the problem.
David Graham, associate director for science and medicine in FDA's Office of Drug Safety, said in Senate testimony Thursday there are serious safety concerns about four currently marketed drugs - - and one in the pipeline.
Graham was testifying about the safety problems that led Merck /zigman2/quotes/209956077/composite MRK +0.12% to withdraw its painkiller Vioxx because of increased risk of heart attack and strokes from regular use.
Graham pointed to Astra Zeneca's /zigman2/quotes/200304487/composite AZN +0.97% cholesterol therapy Crestor, Abbott Laboratories' /zigman2/quotes/203724446/composite ABT +1.41% weight loss drug Meridia, GlaxoSmithKline's /zigman2/quotes/209463850/composite GSK +0.23% asthma drug Serevent, and Pfizer's /zigman2/quotes/202877789/composite PFE +0.14% arthritis drug Bextra as too risky to be prescribed.
Graham also said that Roche's /zigman2/quotes/206948568/delayed RHHVF +3.82% acne drug Accutane -which is linked to birth defects -- needs more controlled distribution to ensure that female patients on the drug are using birth control.
Graham's warnings shook Wall Street, and sent a number of the companies stock plunging on Thursday and Friday.
The FDA said late Thursday that Graham was not speaking for the agency and reiterated that all five drugs are considered safe to prescribe.
Experts weigh in
Martinez said that a major stumbling block in FDA's ability to track the safety of marketed drugs is that the agency has no power to compel companies to do post-market studies.
Martinez said that one of the marketed drugs on Graham's hit list, Serevent, is a good example of a product whose safety profile still has major gaps.
One post-market study, involving 26,000 patients, showed a higher risk of respiratory death in patients taking Serevent than those taking a placebo or other medicines. The higher risk was especially apparent in African-American subjects, Martinez said.