The US Food and Drug Administration has approved the marketing of 5% doxepin hydrochloride cream (Zonalon - GenDerm) for treatment of pruritus due to eczematous dermatoses. Oral doxepin is used as a tricyclic antidepressant (Sinequan, and others).

The FDA has approved a new low-dose formulation of the tricyclic antidepressant doxepin (Silenor – Somaxon) for treatment of insomnia associated with sleep maintenance. The manufacturer claims that this dose retains the hypnotic effect of doxepin, without typical tricyclic adverse effects. Doxepin is available generically in higher-strength capsules and in a liquid formulation.

Cognitive behavioral therapy for insomnia (CBT-I) is recommended for initial treatment of chronic insomnia. CBT-I includes stimulus control, sleep education and hygiene, sleep restriction, relaxation training, and cognitive therapy. When CBT-I alone is not effective, pharmacologic treatment should be added.

In our article on Drugs for Chronic Insomnia, we said there is little evidence that antidepressants such as trazodone, mirtazapine, or amitriptyline are effective in treating insomnia not associated with depression. We received a comment from a reader who has prescribed the tricyclic antidepressant amitriptyline for insomnia, particularly for patients with headache disorders, and finds that most patients are satisfied with the treatment.

View the Expanded Table: Some Oral Drugs for Chronic Insomnia

Bupropion (Wellbutrin - Burroughs Wellcome) was recently marketed in the USA for treatment of depression. First approved by the Food and Drug Administration in late 1985, the drug was withdrawn from the market in early 1986 because of a high incidence of seizures in one study.

The FDA has approved suvorexant (Belsomra – Merck), the first orexin receptor antagonist to become available in the US, for treatment of sleep-onset and/or sleep-maintenance insomnia.

Fluoxetine (Prozac - Dista), a phenylpropylamide, is the first serotonin-reuptake blocker introduced in the USA for treatment of . It is being promoted as causing fewer adverse effects than other antidepressants. Claims of greater safety and patient tolerability have often been made for new non-tricyclic antidepressants in recent years, but unpredicted adverse effects have emerged with widespread use, including priapism with trazodone (Desyrel - Medical Letter, 26:35, 1984) and fatal hemolytic anemia with nomifensine (Merital - Medical Letter, 27:73, 1985).

The physiologic changes that occur with aging can affect the pharmacokinetics and pharmacodynamics of many prescription and over-the-counter drugs, increasing the likelihood of adverse effects.

The FDA has approved lemborexant (Dayvigo – Eisai), an orexin receptor antagonist, for treatment of sleep-onset and/or sleep-maintenance insomnia in adults. It is the second orexin receptor antagonist to be approved for this indication; suvorexant (Belsomra) was the first.