Toxicity of high-dose flurazepam in the elderly.

To assess the potential hazards of flurazepam (Dalmane) therapy of insomnia in the elderly, the relation of dosage and patient age to the frequency of flurazepam-attributed adverse reactions was studied in 2,542 hospitalized medical patients. Adverse reactions, predominantly unwanted residual drowsiness, were reported in 78 flurazepam recipients (3.1%). None of the adverse reactions were serious. The frequency of reported toxicity increased with average daily dose, ranging from 1.3% among those receiving less than 15 mg/day to 12.3% at doses of 30 mg/day or more (p less than 0.001). Toxicity increased with age, progressively from 1.9% among those under 60 to 7.1% among those 80 or over (p less than 0.001). Unwanted effects of high-dose flurazepam were observed much more commonly in the elderly. Only 2.0% of those 70 years of age or older experienced adverse reactions at doses under 15 mg/day, as opposed to 39.0% at 30 mg or more per day. Low doses of flurazepam appear to be safe for elderly individuals, but they are susceptible to unwanted central nervous system depression at high doses.