Proactive Compared with Passive Adverse Event Recognition: Calcium Channel Blocker-associated Edema

This article examines the concept of passive compared with proactive surveillance for monitoring adverse events occurring with antihypertensive medications, using the example of calcium channel blocker (CCB)-induced peripheral edema. Monitoring adverse events and clinical trial safety are important functions and dependent on investigator protocols and data and safety monitoring teams. Compared with proactive surveillance, voluntary reporting systems tend to yield a lower frequency of adverse events occurrence. Limitation of data has the potential to directly influence clinical and prescribing practices. This discussion addresses advantages of proactive surveillance accomplished by patient solicitation of adverse events and investigators' direct clinical examination. A literature search between the years 2000 and 2007 was conducted on MEDLINE for randomized clinical trials and meta-analyses reporting the incidence of dihydropyridine-associated peripheral edema. The incidence of edema was high in clinical trials in which patients were actively questioned about edema development and tended to be higher than reported in the prescribing information. The incidence of dihydropyridine CCB-induced edema appears to be dependent on the method of edema assessment.