Die Bedeutung der Pharmakovigilanz in der Psychiatrie: das AMSP-Projekt (Arzneimittelsicherheit in der Psychiatrie)

Abstract

Data on a marketed drug is often limited to premarketing studies. Due to different factors such as exclusion criteria, limited duration, etc., these data are not very representative. Patient cohorts treated in everyday conditions often present a higher prevalence of comorbidity and, consequently, a higher prevalence of comedications, which have a major impact on the incidence and the types of adverse drug reactions. Moreover, adverse drug reactions with a low incidence may not be observed during clinical trials due to the limited number of subjects included. Adverse drug reactions appearing with a certain latency may not be detected in the case of the study observation period being shorter than the latency. Finally, prescription habits often change after marketing of newer compounds which may be associated with the appearance of new side effects. It is for this reason that many adverse drug reactions are detected only after drug-registration. The efficiency of pharmacovigilance approaches based on spontaneous reporting may be limited by the lack of definition of the monitored population and scarce reporting. The incidence of a given side effect can therefore not be evaluated with this method. The rate of reporting may also notably depend on the type and the severity of the adverse drug events and on the personal experiences of the treating health provider. The AMSP-Project is a prospective multicentre program for active and continuous assessment of adverse drug reactions of marketed psychotropic drugs in psychiatric inpatients under naturalistic conditions of routine clinical treatment. Currently more than 30 Swiss and German hospitals are participating in the project, monitoring 20000 inpatients per year. Severe adverse drug reactions are detected by regular screening of all participating wards by local drug-monitors. Each clinical case and the degree of association between adverse drug reactions and pharmacological treatment is discussed during regional and central conferences held several times per year. In order to estimate the incidence of the assessed adverse drug reactions, all prescriptions are assessed on two reference days per year. These index day surveys may furthermore be used to document the development of the prescription habits and to analyse regional and even national prescribing differences. Besides being a very efficient pharmacovigilance instrument, the AMSP-Project has turned out to be a valuable quality management instrument in as much as it seems to increase the awareness of participating physicians and other health providers of drug safety issues.