Changing patterns of therapeutic agents in the elderly: a ten-year overview.

Drug use patterns in a large ambulatory elderly population were studied cross-sectionally over a 10-year period. There were 24192 drug histories obtained on 4509 individuals during the period from 1 August 1978 to 31 July 1988. The average number of drugs used per person increased from 3.22 in 1978-9 to 3.94 in 1987-8. Prescribed drug use increased by 0.52 per person compared with an increase of 0.21 for nonprescribed medication. Analysis of two mutually exclusive groups of participants from 1978-9 and 1987-8 revealed a significant (p less than 0.0001) increase in the use of nonprescribed medication but no significant increase in the use of prescribed medication after adjusting for age and sex effects. The four most frequently used therapeutic classes of drugs in 1978-9 as a percentage of all drugs used were antihypertensives (10.8%), analgesic-antipyretics (6.4%), antirheumatic (6.4%), and cathartics (5.4%) compared with the antihypertensives (9.5%), analgesic-antipyretics (5.9%), anticoagulants (5.5%), and antirheumatic (4.6%) for the 1987-8 period.