A comparison of two cohort studies evaluating the safety of cisapride: Prescription-Event Monitoring and a large phase IV study

Objective: The results of Prescription-Event Monitoring (PEM) from over 13 000 patients receiving cisapride are compared with safety data from a large-scale clinical study involving nearly 10 000 patients. Results: The clinical study population showed a significantly younger age profile than the PEM population and excluded patients with serious disease; however, both studies showed similar patterns of adverse events. The most common adverse events reported in association with cisapride in both studies were diarrhoea, headache, abdominal pain, constipation and nausea. Some of these may be attributed to the underlying condition rather than the action of the drug. Prompting patients about adverse events during a clinical trial assessment appeared to increase the reporting of some conditions: for example, diarrhoea was reported more frequently in the clinical trial than in the PEM study. Conclusion: Both studies showed cisapride to be generally safe and well tolerated.