Potential risks and prevention, Part 3: Drug-induced threats to life.

Potential risk factors for and the preventability of drug-induced threats to life were studied. Case reports of adverse drug events (ADEs) published in Clin-Alert during 1977-97 were the source of information on drug-induced life threats. 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 846 drug-induced life threats. Seventy-four percent of the cases were assessed as definite or probable. Patients received usual or below-usual dosages in 89% of the cases. Patients tended to be middle-aged and only moderately ill. The drug categories most frequently associated with life threats were antimicrobials and central-nervous-system agents. Plasma drug level monitoring should have been performed in 127 cases but occurred only in 31 cases (24%). Event types were distributed as adverse drug reactions (50%), allergic reactions (35%), drug interactions (11%), and medication errors (4%). A commercial reference classified almost half of the drug interactions associated with a life threat as posing minimal or no potential risk to the patient. Half of the life-threatening events were judged to have been preventable; about half of these could have been prevented by a pharmacist. Litigation was reported for only 1% of the cases of drug-induced threats to life; judgments and settlements averaged $1.2 million. A review of published case reports of ADEs for 1977-97 yielded information on possible risk factors for drug-induced life threats and on which events may have been preventable.