The sudden withdrawal of the blockbuster arthritis drug Vioxx and warnings about similar medications - including heightened suicide risks from antidepressants - have focused unprecedented negative attention on the Food and Drug Administration (FDA). Two congressional committees, the Government Accountability Office and the Institute of Medicine have begun looking at the agency's performance, and several lawmakers are proposing overhauling the way the FDA operates. Critics say the agency suffers from deep-seated flaws, including conflicts of interest, an inattention to safety issues and a lack of enforcement authority. An FDA medical reviewer testified recently the agency's close relationship with the drug industry and its tendency to rush drugs to market has left the country "virtually defenseless." But FDA and drug-industry officials say the U.S. still enjoys the safest drug system in the world and that proposed reforms, including creation of a new safety oversight board, will create transparency and provide a safety backup system.