In a stinging article in the New England Journal of Medicine, a Harvard Medical School professor has accused big drug companies of hiding evidence of adverse results of their products. The latest example, says Dr Jerry Avorn, is Bayer’s behaviour over a drug used in cardiac surgery, aprotinin. On September 21, the Food and Drug Administration decided that despite a negative study in the NEJM, there was no need for an additional warning to consumers. But only a few days later, on September 30, it warned that the drug could cause renal failure, congestive heart failure, stroke or death. What had happened in the meantime was that the FDA had learned that Bayer had commissioned its own report. This confirmed the NEJM study’s conclusions and showed that patients who received aprotinin had substantially higher mortality rates and renal failure. But it withheld the study from the FDA — which Bayer later described as “a mistake”.

Dr Avorn feels that drug companies often fail to reveal adverse results, even though the health care system relies upon them to provide most of the safety data. “It is na?ve to expect companies to voluntarily fund studies that could sink lucrative products [and] the FDA lacks the clout to require them,” he writes. His solution is to propose publicly supported studies of drug risks whose data will be open to all researchers.