[Use of databases in pharmacovigilance: two examples]

The association between asthma exacerbations and use of antiasthmatics has been studied with a drug dispensing database. Exacerbations were identified through use of oral corticosteroids and the risk was determined for each medication. use of fenoterol and oral xanthines increases the frequency of exacerbations, but a channelling phenomenon is not excluded. This method could be used in the study of treatment combinations or new treatments, facilitating the monitoring of asthmatic populations. A second study collects ambulatory drug use data (POM and OTC drugs) of elderly patients. These data are analysed for the distribution of several variables, such as concomitant use of several medications of the same therapeutic class. As an example, about 15 per cent of NSAIDs users also use aspirin, exposing themselves to increased risk for gastrointestinal effects. These studies illustrate the use of drug dispensing databases in monitoring populations at risk and assessing treatment quality.