The way towards adverse event monitoring in clinical trials.

Different approaches to the monitoring of adverse reactions to drugs have been used over the years, with the aim of preventing catastrophes like the thalidomide episode and to rationalise drug usage. In the 1960s, the use of national and international adverse event monitoring was first suggested by the British statistician, David Finney. According to Finney, the method was well suited for the postmarketing surveillance of drugs. The idea was rejected by the World Health Organization (WHO) but was later taken up by the Prescription Event Monitoring Event System in the UK. Subsequent to problems with practolol in the 1970s it was suggested that adverse event monitoring could also be useful in clinical trials to detect adverse reactions before a drug is launched. The idea of adverse event monitoring has been tested by Astra Hässle in Sweden in clinical trials with felodipine and omeprazole, and is now the standard method within the company. Adverse event monitoring is an expensive and time-consuming method seen from a short term perspective. However, such monitoring offers an opportunity to optimise the use of clinical trials in safety monitoring, and its ability to predict possible adverse drug reactions is superior to other methods.