OBJECTIVE: To provide detailed demographic profiles of prescription drug utilization and expenditures in order to isolate the impact of demographic change from other factors that affect drug expenditure trends. DATA SOURCES/STUDY SETTING: Demographic information and drug utilization data were extracted for virtually the entire British Columbia (BC) population of 1996 and 2002. All residents had public medical and hospital insurance; however their drug coverage resembled the mix of private and public insurance in the United States. STUDY DESIGN: A series of research variables were constructed to illustrate profiles of drug expenditures and drug utilization across 96 age/sex strata. DATA COLLECTION/EXTRACTION METHODS: Drug use and expenditure information was extracted from the BC PharmaNet, a computer network connecting all pharmacies in the province. PRINCIPAL FINDINGS: Per capita drug expenditures increased at an average annual rate of 10.8 percent between 1996 and 2002. Population aging explained 1.0 points of this annual rate of expenditure growth; the balance was attributable to rising age/sex-specific drug expenditures. CONCLUSIONS: Relatively little of the observed increase in drug expenditures in BC could be attributed to demographic change. Most of the expenditure increase stemmed from the age/sex-specific quantity and type of drugs purchased. The sustainability of drug spending therefore depends not on outside forces but on decisions made by policy makers, prescribers, and patients.