Features of the French postmarketing drug surveillance system. Application to cutaneous effects of nonsteroidal antiinflammatory drugs.

The French drug surveillance system is characterized by several original features: 29 regional centers in France collect, analyze and enter the adverse drug reactions (ADR) in a national data bank; reporting of severe ADR by prescribers is mandatory; data are collected either as spontaneous reports (warming-step) from prescribers or by direct request when an intensive validation study is set up from the data of the spontaneous reports; each validation study evaluates only well documented cases which thus can lead to a decision of imputability to assess the drug effect relationship; the reaction time of the system is fast: severe ADR (agranulocytosis, Lyell's syndrome) can be identified as soon as they occur, and it takes less than one year between the first warning case report and the final restrictive decisions for any drug concerned. Such a system answers the question whether an individual patient in a drug treated group developed the adverse reaction because of the drug. This type of analysis can lead to emphasis on some special features, pathological causes, genetic or environmental factors, pharmacological causes, which may serve to initiate epidemiological studies as a next step. These studies can indicate, in statistical terms, a greater occurrence of an ADR group and thus are an aid to define the population at risk. The results of a national inquiry on cutaneous adverse effects of nonsteroidal antiinflammatory drugs observed in France in 1985 have led to an original classification of drugs regarding that risk.