Adverse reactions to anticoagulants and to antiplatelet drugs recorded by the German spontaneous reporting system.

According to their code of professional conduct, German physicians are obliged to report suspected cases of adverse drug reactions (ADRs) to the Drug Commission of the German Medical Association (AkdA). On the basis of an agreement between the German Medical Association and the Federal Institute for Drugs and Medical Devices (BfArM) a common pharmacovigilance database within the German spontaneous reporting system was created. A user-friendly application program developed in-house enables the user to conduct searches about reported ADRs covering a wide variety of questions within a short period of time. ADRs caused by anticoagulants and by antiplatelet drugs still belong to the most reported adverse events. The most frequently reported suspected drugs are heparins, followed by ticlopidine, phenprocoumon, acetylsalicylic acid, and clopidogrel. Bleeding complications are the most often described ADR symptoms of any anticoagulation therapy, especially of phenprocoumon and acetylsalicylic acid. Another serious ADR is heparin-induced thrombocytopenia or changes in blood counts (CBC) due to ticlopidine and clopidogrel. During the past few years a reduction in severe reactions, such as cerebral hemorrhage, especially with fatal outcome was detectable because of better clinical management of oral anticoagulant therapy and of adverse events concerning heparin.