Review of Prescription Therapy for Insomnia

Article excerpt

Continuing Education

Wyeth

TRENDS IN PHARMACY AND PHARMACEUTICAL CARE

Epidemiology

The most recent epidemiological surveys indicate that approximately one-third of the population suffers from occasional difficulty in sleeping. Moreover, it is estimated that some 35 million Americans suffer from chronic insomnia. Insomnia tends to be worse in women, and sleep difficulties increase with age in both genders. However, these generalizations must be qualified, since patient perception of sleep is often skewed. Typically, patients overestimate the time that is required for onset of sleep and underestimate the number of nighttime awakenings, as compared with polysomnographic assessment of sleep behavior.

Patients often perceive their problems with sleeping as falling into one of three classes: (1) trouble falling asleep, (2) frequent awakenings after falling asleep, or (3) early awakening with an inability to resume sleep. These subjective perceptions are important in choosing appropriate therapy. The more clinical definitions of insomnia must also be considered in choosing the most appropriate therapy. Sleepstudy units across the nation typically define three types of insomnia. Transient insomnia is the inability to sleep well over a relatively short period (i.e., less than one week). This is most often attributed to external factors, such as personal confrontations, anticipation of a trip or event, or inappropriate nighttime exercising or meals, and is often due to stress or excitement. Short-term insomnia, resulting from prolonged periods of stress, may last for two to three weeks. As is the case with transient insomnia, once the stressful situation has passed, sleep generally returns to that patient's normal pattern.

Chronic insomnia is more dangerous to the patient since it may last for months, and the subsequent sleep deprivation and lack of restorative sleep may lead to other health consequences. Chronic insomnia may result from other chronic diseases or prolonged stress, or it may arise from some unknown factor.

Additionally, some sleep experts classify insomnia as either acute or chronic and as either primary or secondary. Either acute or chronic insomnia may be secondary to some other causative situation. Acute or transient insomnia often results from sudden changes in daily routine or a sudden stress in the life of the patient. Examples of these may include sudden shifts in time zone (i.e., jet lag); personal conflicts (such as spousal/marital difficulties, financial worries, a death in the family); and abnormal eating, drinking, or exercise behaviors.

Chronic insomnia may be secondary to a diagnosable psychiatric disease, such as depression or psychosis, or to substance abuse and addiction (including both alcohol and nicotine). Additionally, certain habits such as large evening meals (especially within two to four hours of bedtime), evening exercise within the same time frame, or excessive television watching or reading in bed immediately prior to sleep may cause sleep difficulties. Either transient or chronic insomnia may also be secondary to a preexisting medical condition, such as arthritis, peptic ulcer disease, cardiovascular disease, any of the chronic obstructive pulmonary diseases, numerous psychiatric conditions (e.g., OCD, depression, anxiety and panic disorders), and sleep apnea.

Drug therapy may also be a major cause of secondary insomnia, with many drug classes possessing the ability to interfere with sleep. This list includes, but is certainly not limited to, any central nervous system stimulant (including over-the-counter decongestants and caffeine), diuretics (by increased need to void during the night), corticosteroids, antihypertensives, and antidepressants. Both selective serotonin reuptake inhibitors (SSRIs) and tricyclic antidepressants may disturb normal sleep patterns. Many of the drugs that alter sleep may do so while possessing sedation as a major side effect (e. …