This article provides national estimates of drug use and drug expenditures in 1982. Total outpatient drug exposure increased 5% from 1981 to 1982 and 28% from 1971 to 1982. Hydrochlorothiazide was the most frequently dispensed drug chemical and was contained in more than 5% of all 1982 prescriptions. Sixteen major therapeutic classes accounted for about 80% of drugstore and hospital expenditures for ethical pharmaceuticals. Hospitals spent around $3.0 billion and a third of this total was for anti-infectives administered for systemic effects. The prescription drug component of the consumer price index increased 11.7% in 1982, and consumers spent about $14.5 billion on prescriptions from retail pharmacies alone. (JAMA 1985;253:382-386)