Effects of central nervous system polypharmacy on falls liability in community-dwelling elderly

While central nervous system (CNS) active medications such as psychotropics and narcotic analgesics have been implicated in contributing to falls in older adults, the combined effect of multiple CNS-active medications has not been investigated. The purpose of this study was to examine the influence, in community-dwelling elderly, of (1) taking multiple CNS-active medications on fall liability and (2) individual classes of CNS-active medications (using discrete drug classification) on the risk of falls after controlling for important confounders--age, mobility, cognition and depression.

305 community-dwelling male veterans (age: 70-104) were screened at study entry for mobility, cognition and depression. CNS-active medications were categorized as benzodiazepines, other sedative-hypnotics, neuroleptics, tricyclic antidepressants, and opioid analgesics. Subjects were prospectively followed for 6 months to monitor falls; at the end of this time period, subjects were classified as fallers (at least one fall) or nonfallers. The relationship between CNS-active drug use and falls was examined using multivariable analyses.

The risk of falls was significantly greater in CNS-active medication users as compared with nonusers. Adjusted odds ratio for one CNS-active drug was 1.54 (95% confidence interval 1.07-2.22) and for two or more agents 2.37 (95% confidence interval 1.14-4.94).

In community-dwelling elderly, the use of multiple CNS-active medications is associated with enhanced falls liability, over and above the use of one CNS-active drug alone. This apparent dose-response relationship provides support for causality.