COUMARIN-INDUCED HEPATIC-INJURY - EXPERIE NCE OF SWISS DRUG-MONITORING CENTERS SANZ AND IKS

Drug-induced liver diseases are potentially avoidable. Hepatotoxic dru gs can mimic virtually any form of liver disease. Among all voluntary adverse drug reaction reports to central registries, 4-7% refer to dru g-induced liver diseases. We analyze all cases of coumarin-induced hep atic injuries reported on a voluntary basis to the Swiss Drug Monitori ng Centre (SANZ) and the Pharmacovigilance Centre (IKS) from 1981 to 1 995. During this period the SANZ collected 9720 reports, 674 of which (6.9%) referred to the liver and the biliary tract. In only 11 reports an oral anticoagulant was involved. In 8 cases we assumed at least a possible causal relationship. 2 more cases were reported directly to t he IKS. Among these 10 cases 7 were related to phenprocoumon and 3 to acenocoumarol. In 4 cases elevated concentrations of liver enzymes wer e measured 2-7 days after the beginning of therapy. In the remaining 6 cases the clinical picture was so severe that the patients had to be hospitalized. These 10 cases are discussed and compared with the cases published in the literature. According to our data, hepatic disorders induced by coumarin-anticoagulants are rare. If hepatitis is diagnose d in a patient treated with oral anticoagulants, the differential diag nosis of a coumarin-induced hepatic injury has to be considered. Cross -reactions between the coumarin derivatives phenprocoumon and acenocou marol are possible.