Aging and heavy drug use: a prescription survey in Manitoba.

A random sample of claimants under Manitoba's Pharmacare plan provided information on the drugs prescribed for those individuals who spent more than $50 for drugs in 1978. More women than men were represented among the 412 claimants aged 50 to 64 (58% females), and more drugs were prescribed for women than men (8.38 +/- 3.4 vs. 7.17 +/- .33, mean +/- S.E.M., p less than 0.02). For the 403 claimants aged 65 and older, the sex distribution matched that of the general population (55%), and the difference in number of drugs prescribed was not statistically significant (8.49 +/- .36 vs 7.98 +/- .35). For the claimants aged 65 and older, the five most heavily prescribed drug categories were thiazide-type diuretics (prescribed for 51.6% of older claimants in 1978), benzodiazepines (40.0%), salicylates (26.8%), digoxin (22.6%) and codeine (20.8%). There were few differences in prescription frequencies between younger and older claimants, and these data indicate that drugs prescribed for heavy drug users do not change markedly as a function of age.