Objectives:

To quantify known associations between the three-blood dyscrasias and drug use.

To identify and quantify previously unsuspected associations of drug use.

To document absence of associations for commonly used drugs.

Methods:

The methods were modeled on the IAAAS. Cases of agranulocytosis, aplastic anemia, and thrombocytopenia purpura were ascertained through regular telephone calls to hematologists, pathologists and/or laboratory technicians, in participating hospitals serving a total population of 10 million in the Boston and Philadelphia areas. Specially trained nurse monitors interviewed cases and controls of the same age and sex that were admitted to hospital for acute conditions unrelated to drug use. Information obtained included the patient's general medical background, medication usage within the six months prior to admission and exposure to radiation and chemicals. Bone marrow biopsies or aspirations, peripheral blood smears and all relevant laboratory data were obtained for each interviewed case. The hematologic data were referred to the study's Hematological Review Committee to establish the final diagnosis without knowledge of drug exposure. Some 45 cases of aplastic anemia, 70 of agranulocytosis, 300 of thrombocytopenia, and 3300 control subjects were studied.

Results:

An evaluation of acute thrombocytopenic purpura in relation to drug use demonstrated associations with trimethoprim/sulfamethoxazole (RR estimate, 124), quinidine (101), dipyridamole (14), sulfonylureas (4.8), and salicylates (2.6). With an estimated annual incidence of of 18 cases per million, excess risk estimates were quite low. The data on agranulocytosis and aplastic anemia were combined with two other large studies that we conducted (the IAAAS and Thai Studies of Aplastic Anemia and Agranulocytosis), to maximize the available information on those rare dyscrasias.

Investigators:

David Kaufman, Sc.D., Principal Investigator
Judith Kelly, M.S., Co-Investigator
Paul D. Stolley, M.D., Co-Investigator
Samuel Shapiro, M.B., F.R.C.P.(E), Co-Investigator

Source of funding:

National Heart Lung and Blood Institute

Study Period:

February 1983 - November 1991

Publications:

Link to Publications