DOES PROOF OF CAUSALITY EVER EXIST IN PHARMACOVIGILANCE

Identifying the adverse effects of drugs, thus transforming adverse ev ents into adverse drug reactions, is a useful and necessary but compli cated task. Objective proof of a causal relationship between a drug an d a specific event is quite exceptional. In most cases, this relations hip remains subjective and is no more than inner conviction. Several m eans are at our disposal to achieve causal assessment: spontaneous rep orting, clinical trials, cohorts with and without controls, and case-c ontrol studies, with each having advantages and limitations. The searc h for causality in pharmacovigilance is a necessary scientific goal, b ut a high degree of suspicion may be all that is necessary to withdraw a drug from the market if it is suspected of causing serious adverse effects.