Potential risks and prevention, part 1: Fatal adverse drug events

Potential risk factors for and the preventability of fatal adverse drug events (ADEs) were studied. Case reports of ADEs published in Clin-Alert during 1976-95 were the source of information on fatal ADEs. Patient, drug, and event variables were identified, and the causality, predictability, and preventability of each case were assessed. Data were entered into a relational database for analysis. The data indicated 447 cases involving a fatal ADE. Ten percent of the fatal ADEs were assessed as definite, 46% as probable, and 44% as possible. Fatal-ADE frequency increased with age. Forty-five percent of the patients were 40-69 years of age, and 40% were healthy. Central-nervous-system agents, antineoplastics, antimicrobials, and cardiovascular agents accounted for 69% of the deaths. Only 33% of patients received more than the usual dosage. Many of the suspected drugs could have been monitored with blood level tests but were not, and baseline testing of critical blood count and liver and renal function was often not performed. The most common causes of death were hepatitis, hepatic failure, cardiopulmonary arrest, overdose, and agranulocytosis. ADE types were distributed as adverse drug reactions (58%), allergic reactions (19%), medication errors (17%), acid drug interactions (6%). Sixty-eight percent of the fatal ADEs were judged to have been preventable: of these, a pharmacist could have prevented 57%. Litigation was reported for 14% of the fatal-ADE cases; judgments and settlements averaged $1.1 million. A review of published case reports of ADEs for 1975-95 yielded information on possible risk factors for fatal ADEs and on which events may have been preventable.