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The Vioxx warning

FOR FOUR years, researchers have been pointing to disturbing signs that the popular painkilling drug Vioxx causes heart attacks and strokes with long-term use. Last week the pharmaceutical giant Merck voluntarily withdrew the drug from the market after a recent study confirmed this side effect. The rise and fall of Vioxx highlights the need for longer studies before the Food and Drug Administration approves new medications that will often be taken by patients for extended periods of time and lack the urgency of life-saving treatments. At $2.5 billion in annual sales, Vioxx is the biggest-selling drug any company has ever recalled. In its five-year history it became widely prescribed as a painkiller for arthritis patients, since it did not cause ulcers or stomach bleeding. The study that confirmed its link to cardiovascular problems was actually designed to determine whether Vioxx might also prevent the recurrence of colon polyps that could become cancerous.

But critics of the drug had long voiced the suspicion that it caused heart problems. In a 2000 study, Vioxx did somewhat better than another, generic painkiller in not causing ulcers or gastrointestinal bleeding. When that study also showed more nonfatal heart attacks in Vioxx patients than in those taking the other drug, Merck attributed the difference to a heart-protective effect it said the other drug had. By 2002, the FDA had seen enough evidence of heart-related problems with Vioxx to require a label warning. It should have also required a thorough study at that point.

In the test of Vioxx as a preventer of colon polyps, the heart problems emerged after 18 months of daily use. The testing that led to the drug's original approval lasted just 12 months.

The most immediate task for the FDA is to order long-term studies of possible cardiovascular problems in users of prescription painkillers similar to Vioxx, such as Celebrex. But after the Vioxx recall and others in recent years, the agency should also examine whether it is letting medications come onto the market before their long-term effects have been sufficiently tested.

Critics of the FDA in the pharmaceutical industry and Congress often take the agency to task for delaying unnecessarily the approval of new drugs. While that criticism might be valid in the case of life-saving or life-extending drugs for patients with cancer or other extreme conditions, the only reason for speedy approval of drugs like Vioxx, which simply improve on other painkillers, is to give the maker a longer period under patent protection. However, there is a risk that a short trial period will not detect side effects in drugs for chronic conditions that might be taken by some patients for years. Patients with cardiovascular problems worsened by Vioxx have paid for that rush to market. 

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