Sleep

When sleep disruptions are severe and unresponsive to behavioral and environmental strategies, a pharmacological approach may be warranted, but these must be acknowledged to be symptomatic and not a cure for the underlying causes of sleep disturbances. Because of the high incidence of insomnia among older people, they are frequent consumers of both prescription and nonprescription sedatives. However, since they typically have increased sensitivity and reduced ability to metabolize these same drugs, physicians must monitor these treatments carefully to avoid overdoses and increased risks of falls, accidents, and daytime confusion or cognitive problems.

Barbiturates are rarely used today to aid sleep because of high risks of toxicity, tolerance, dependence, and the potential for life-threatening interactions with other medications. Benzodiazepines are currently the most commonly prescribed medications for sleep problems. Relative to barbiturates, they have a wider safety margin between effective and toxic doses and less potential for development of tolerance (the need for a progressively larger dose to achieve equivalent effects). They can, however, pose serious health threats when used in conjunction with sedating medications or alcohol, especially in older people. Benzodiazepines increase stage 2 sleep but reduce amounts of SWS; thus, they may aid sleep onset and/or maintenance but alter its characteristics.

Different benzodiazepines may be short-, intermediate-, or long-acting. Short-acting benzodiazepines can reduce the time it takes to fall asleep, but may not aid sleep maintenance, and thus may exacerbate early-morning insomnia. Intermediate-acting drugs have effects that last throughout the night and into early morning. Long-acting benzodiazepines are also effective in both initiating and maintaining sleep, but may lead to daytime sedation and impaired cognitive and psychomotor performance. These residual or hangover effects may contribute to increased confusion, falls, and memory disturbances. Another serious problem associated with prolonged use of benzodiazepines is rebound insomnia—an increase in sleep disruption after withdrawal of the drug—which may be worse than the original sleep complaint. Thus, benzodiazepines are best used as a short-term sleep aid, rather than as a long-term maintenance strategy for sleep.

Benzodiazepines are not the sedative of choice in two situations. When insomnia arises from depression, an antidepressant with sedative properties may be a preferred treatment. The antidepressant effect is typically delayed for two weeks or more, but the sedative property can improve sleep shortly after initiating treatment. Patients with symptoms of sleep apnea should avoid sedating medications because these have respiratory depressant properties, which may worsen the symptoms of sleep apnea.

Nonbenzodiazepine sedatives, which have been marketed in some countries, act on similar brain mechanisms, but in a different way. These drugs (zopiclone and zolpidem) are short-acting and have been reported to have fewer unwanted effects than benzodiazepines. They cause less residual daytime anxiety than some short-acting benzodiazepines, fewer cognitive effects than longer-acting drugs, appear to have little abuse potential, and are reported not to generate rebound insomnia after discontinuation. Because of their short action, they are useful for sleep initiation, but they are less useful for treating early morning insomnia.