Effect of hypnotic drugs on body balance and standing steadiness

Summary

Background

Disturbed body balance and standing steadiness are problematic for those who wake up at night or in the morning after using hypnotic drugs. As a result, falls and hip fractures are frequently reported in patients using sleep medication.

Methods

A literature search was performed to identify double blind, placebo-controlled clinical trials that examined body balance and standing steadiness. Drugs that were searched were nitrazepam, triazolam, lorazepam, temazepam, loprazolam, flunitrazepam, flurazepam, and the Z-drugs zopiclone, zolpidem and zaleplon.

Results

A total of 57 studies were eligible for inclusion. Results showed that both benzodiazepine hypnotics and the Z-drugs significantly impair body balance and standing steadiness after single dose administration. Impairments correlate significantly with blood plasma levels and are greatest at peak plasma concentrations, but are sometimes still present upon awakening. Balance problems were dose-related and most pronounced in elderly. Co-administration of alcohol aggravated the impairment. After repeated daily use of hypnotic drugs partial tolerance develops to the impairing effects on standing steadiness.

Conclusion

Single dose administration of benzodiazepine hypnotics and Z-drugs significantly impair body balance in a dose-dependent manner. Zolpidem and zopiclone produced similar significant impairment as benzodiazepine hypnotics. Zaleplon significantly impaired balance up to 2 h after intake. Partial tolerance develops after repeated daily use. In conclusion, patients should be warned about the possible risk of imbalance and falls due to the use of sleep medication.

Introduction

Most falls occur during daytime and are related to imbalance and postural instability. Slippery sidewalks, irregular surfaces (e.g., a bobbling carpet) and bad luck account for the majority of falls.1, 2 Approximately 20% of falls occur at night. Falls are most common among elderly; about 30% of elderly experience at least one fall yearly. The majority of these falls have no serious consequences, but 20–30% of falls result in injury, hip-factures or even death. For example, in 2001, over 15,000 deaths from falls were reported in the USA. In contrast to young adults, elderly recover much slower from injury, if at all. Indeed, increased mortality rates have been reported in elderly who have been involved in falling accidents resulting in hip fracture.*3, 4, 5The economic burden of non-fatal falls is significant. For the USA, it has been estimated that over 20 billion dollars yearly are spend on medical costs related to falls.6, 7 Various studies have associated the use of hypnotic drugs, including benzodiazepines and zopiclone, with postural instability and an increased risk of falls and hip fractures.8, *9 Hypnotic drugs can have an effect on functions that are not related to sleep. Some of these may be of importance in postural control, which is governed by a number of processes such as sensory, cognitive and motor processes.² This review discusses the clinical trials that examined the effects of hypnotics on body balance and postural stability.