Medication misadventures resulting in emergency department visits at and HMO medical center.

Medication misadventures resulting in visits to the emergency department of a health maintenance organization (HMO) were studied. The records of patients who visited the emergency department at a California HMO between August 1992 and August 1993 were evaluated for evidence of medication misadventures brought to the department. The definition of misadventure included noncompliance and inappropriate prescribing but excluded intentional overdoses and substance abuse. If it seemed probable that a misadventure occurred, a pharmacist interviewed the patient by telephone. During the 12-month study, 1,074 (1.7%) of 62,216 visits to the emergency department were due to medication misadventures. The patients who had had a misadventure were predominantly female (62%); 38% were 15-44 years of age and 33% were 65 or older. Interviews were possible with 962 patients. Only 30.6% of the patients had a good understanding of the potential adverse effects of their regimen, and only 29.0% had a good understanding of the potential interactions. Misadventures were most often due to allergies or medication underuse among patients < or = 14 years of age and to adverse effects and inappropriate dosage in elderly patients. Of the 1,074 misadventures, 152 (14.1%) resulted in hospital admission. Three areas of particular concern were identified (1) noncompliance with respiratory agents in the young, (2) nonsteroidal anti-inflammatory use leading to hospital admission, and (3) the frequency of problems in the elderly. Medication misadventures accounted for 1.7% of emergency department visits and 1.0% of hospital admissions at an HMO medical center.