Drug-induced blood disorders.

A case-history study of drug-induced blood disorders (pancytopenia, hemolytic anemia, thrombocytopenia, and granulocytopenia) was carried out at the Group Health Cooperative of Puget Sound, a health maintenance organization with more than 200,000 members, for the ten-year period from 1972 through 1981. During this time, only 26 instances of hospitalization for such disorders were thought to be definitely, probably, or possibly due to drugs other than antitumor agents. The rate was of the order of one per 100,000 person-years at risk. Only quinidine/quinine and sulfa-containing drugs were implicated in more than one case.