The (off-label) use of sedating antidepressants for the treatment of chronic insomnia has increased substantially over the past 20 years, representing a notable shift away from the use of benzodiazepines.1 In fact, a survey has found that the antidepressant trazodone is the most frequently prescribed of all drugs for insomnia in the US.2,3 In Europe, the most commonly prescribed antidepressant for the treatment of insomnia symptoms include trazodone, amitryptyline, and mirtazepine.4 Despite their frequent use, none of the antidepressants are indicated for the treatment of insomnia, their efficacy as hypnotics is not well studied, and dose– response relationships have yet to be established.5,6 Furthermore, all sedative antidepressants have the potential to produce significant side effects (at antidepressant doses), which raises concerns over their risk/benefit profiles when used for ‘off-label’ conditions such as insomnia.3
References:
1. Walsh JK, Schweitzer PK. Ten-year trends in the pharmacological treatment of insomnia. Sleep 1999; 22 (3): 371–375.
2. Mendelson WB, Roth T, Cassella J, et al. The treatment of chronic insomnia: drug indications, chronic use and abuse liability. Summary of a 2001 New Clinical Drug Evaluation Unit meeting symposium. Sleep Med Rev 2004; 8 (1): 7–17.
3. National Institute of Health. NIH State of the Science Conference statement on manifestations and management of chronic insomnia in adults statement. J Clin Sleep Med 2005; 1 (4): 412–421.
4. Harris International, 2006.
5. Nau SD, Lichstein KL. Insomnia: causes and treatments. In: Carney PR, Berry RB, Geyer JD, eds. Clinical Sleep Disorders. Philadelphia: Lippincott Williams & Wilkins, 2005: 157–190.
6. Lieberman JA. Update on the safety considerations in the management of insomnia with hypnotics: incorporating modified-release formulations into primary care. Prim Care Companion J Clin Psychiatry 2007; 9 (1): 25–31.