ABSTRACT
The Farmacotherapeutisch Kompas (FK) and the KNMP Kennisbank report on side effects of medicinal products, in order of frequency. However, data regarding causality and its assessment are lacking, while this information is crucial when the discontinuation of a drug due to putative side effects is considered. In this article, we describe the role of pharmaceutical companies, the agencies in charge of the evaluation and supervision of medicinal products and Lareb. We also describe how this information is included in the FK and the Kennisbank. Only side effects with a probable causal relation to the drug are registered. However, to err on the side of caution, side effects with a questionable causal relation to the drug are sometimes also registered. It would be helpful for the physician if the FK and the Kennisbank also reported the degree of assessed causality, next to the frequency.