Sleep disorders: Pharmacotherapy
Sleep-promoting agents (hypnotics or sedatives) are generally recommended for short-term treatment of insomnia. Some sedating agents have the potential for physical or psychological dependence and there are limited studies on the effects of long-term hypnotic use. For the available range of pharmacotherapies for sleep disorders, (see Table 12.1: Pharmacotherapies for sleep disorders).
In situations where insomnia presents with another illness, insomnia should be considered a comorbid condition rather than simply a manifestation of the other illness. The insomnia should be specifically targeted for treatment.
Taking a hypnotic does not decrease the need for psychoeducation and cognitive-behavioural intervention. Similarly, long-term hypnotic use should not be denied if the patient is clearly benefitting. The cost–benefit balance needs to include an awareness of, for example, the fact that patients with insomnia have twice the rate of motor vehicle accidents. As with all long-term treatments, monitoring and re-evaluating the underlying condition should be stringent and may be done best in a specialized clinic.
Most current hypnotics/sedatives are more effective for the symptomatic treatment of sleep-initiation insomnia than for sleep-maintenance insomnia.
Some novel medications have been developed specifically for the treatment of insomnia, while others have been used in the past decades because of their sedative side-effects. The former include the "Z-drugs" zopiclone, zaleplon and zolpidem and the melatonin receptor agonist ramelteon. Of these, only zopiclone (Imovane) is currently available in Canada, although zaleplon can be obtained from a compounding pharmacy.
With the appearance of these specific hypnotics, the benzodiazepines have become less commonly prescribed for insomnia.
Recently L-tryptophan (Tryptan), an essential amino acid and the precursor of serotonin, has been increasingly used. Using hypnotics in children is viewed as less desirable and a parsimonious solution is to use tryptophan at an increasing dosage to gain a hypnotic effect.
Melatonin is a hormone produced in the pineal gland with a strong chronobiotic effect and a less pronounced hypnotic effect. It is the first choice treatment for delayed sleep phase syndrome, especially if the impaired melatonin production is proven by a specific (dim light melatonin onset) test.
Although melatonin is used widely as a hypnotic, this unregulated use does not take into account potential risk of melatonin use, especially in younger patients. There is no other hormone so casually prescribed as melatonin.
Excessive daytime sleepiness
The pharmacological (and other) treatment of excessive sleepiness should be specific to the underlying problem. The paradoxical use of a hypnotic can be useful if there is no other specific cause for excessive sleepiness other than repeated, spontaneous arousals recorded at the sleep lab. The best approach is often a course of treatment lasting two months, with a review approximately two to four weeks after stopping the medication.