Millions of patients are afflicted by a variety of sleep disorders. Sleep can be measured electrophysiologically and described in terms of nonrapid eye movement (NREM) and rapid eye movement (REM) sleep, with REM sleep being dream sleep. Overall, sleep is a cyclic phenomenon, showing a 90-minute periodicity. Sleep disorders are divided into four groups: disorders of initiating and maintaining sleep, disorders of excessive somnolence, disorders of the sleep-wake schedule, and the parasomnias. The parasomnias include sleepwalking, sleep terror, and nightmares. The classic disorders of excessive somnolence include obstructive sleep apnea (an impairment of respiratory function during sleep) and narcolepsy (a genetically transmitted dysregulation of REM sleep). Insomnia may be either transient (eg, associated with jet lag, work shift change, or a disturbing or exciting situation) or chronic (eg, associated with psychiatric disorders or periodic leg movements during sleep). Hypnotics are generally reserved for the treatment of transient or short-term insomnias. Although a number of hypnotics are available, the benzodiazepines are currently accepted as the drugs of choice; selection within the group is based primarily on differences in pharmacokinetic profiles. The practicing pharmacist has the opportunity to play an important role in assessing, recommending treatment, or recommending further evaluation for the many patients who present with insomnia or excessive daytime sleepiness.
Disorders of Excessive Somnolence
