Abstract
A consensus process was used to establish an agreed list of important adverse reactions to drugs identified since thalidomide. Ten physicians working in medicine in Britain and 10 physicians responsible for drug regulatory agencies in different countries were asked to list 10 important adverse reactions to drugs since thalidomide. From these 20 lists a measure of agreement was apparent. Eighteen important adverse reactions were identified for further study of the discovery processes now operating and of the delays occurring from marketing to alerting, from alerting to verification, and from verification to regulatory action. The results suggest that an empirical review of this type is necessary as a starting point for discussion of better systems to reduce delays in the discovery of adverse reactions to new drugs.