For four decades, spontaneous reporting has been the main mechanism by which adverse drug reactions are identified after a medicine is released onto the market, and the Australian program has been exceptionally effective. However, spontaneous reporting programs are limited in their ability to identify an association between a drug and an outcome that is common among the users independent of drug use, and they are not sufficiently sensitive to detect a small increase in the risk of certain rare events. In particular, the increasing long-term use of medication for prevention and control of chronic disease in otherwise healthy individuals presents a challenge to which current postmarketing surveillance mechanisms cannot effectively respond. For example, spontaneous reporting cannot detect an increased rate of myocardial infarction associated with hormone replacement therapy, rosiglitazone or rofecoxib; demonstration of these associations requires large, long-term randomised controlled trials.

©The Medical Journal of Australia 2009 www.mja.com.au PRINT ISSN: 0025-729X ONLINE ISSN: 1326-5377