DIGITOXIN-INDUCED THROMBOCYTOPENIA

A case of severe immune thrombocytopenia following administration of a n excessive dose of acetyldigitoxin is reported. Platelet counts retur ned to normal after discontinuation of the drug. The incidence of this complication is probably underestimated. Clinical symptoms and labora tory tests abnormalities are reviewed. The mechanism is always excessi ve platelet destruction caused by an immune response. Thrombocytopenia seems to occur only when plasma digitoxin levels exceed the therapeut ic range. Platelet counts return to normal only when plasma digitoxin levels decline following discontinuation of the drug. This dependency on the dose, which is not a usual feature of immune thrombocytopenia, is ascribable to the pharmacological properties of acetyldigitoxin.