Procainamide-induced agranulocytosis and thrombocytopenia.

Procainamide therapy has frequently been reported as a cause of agranulocytosis, but severe thrombocytopenia associated with the use of this drug has been noted only once. We report a case of simultaneously occurring agranulocytosis and profound thrombocytopenia in a patient receiving procainamide hydrochloride. Different mechanisms appeared to be responsible for the two cytopenias.