Potential risks and prevention, Part 2: Drug-induced permanent disabilities.

Potential risk factors for and the preventability of drug-induced permanent disabilities were studied. Case reports of adverse drug events (ADEs) published in Clin-Alert during 1978-97 were the source of information on drug-induced permanent disabilities. 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 227 cases of drug-induced permanent disabilities. Twenty-three percent of the cases were assessed as definite, 47% as probable, and 30% as possible. Twenty-nine percent of the patients were less than 10 years old, and 36% were considered healthy. The drug categories most commonly associated with a drug-induced permanent disability were antimicrobials, vaccines, central-nervous-system agents, and antineoplastics. About half of the patients received more than the usual dosage. The most common permanent disabilities were brain damage, blindness, tardive dyskinesia, deafness, quadriplegia, and hearing loss. Event types were distributed as medication errors (55%), adverse drug reactions (43%), and drug interactions (2%). Eighty-four percent of the drug-induced permanent disabilities were judged to have been preventable; of these, a pharmacist could have prevented 40%. Litigation was reported for 56% of the cases of drug-induced permanent disability; judgments and settlements averaged $4.3 million. A review of published case reports of ADEs for 1978-97 yielded information on possible risk factors for drug-induced permanent disabilities and on which events may have been preventable.