Pharmacology · Sedative-Hypnotic Drugs
Three mechanistically distinct alternatives to benzodiazepines for insomnia
Abbreviations: FDA = Food and Drug Administration · IR = immediate release · REM = rapid eye movement · MT1/MT2 = melatonin receptor subtypes · DORA = dual orexin receptor antagonist · CYP1A2 = cytochrome P450 1A2
| Agent | Half-Life | Best For | Key Feature | Caution |
|---|---|---|---|---|
| Zolpidem | 1.5–2.5 hours (IR) | Sleep onset | Most prescribed hypnotic in US. FDA lowered dose to 5 mg for women in 2013. | Next-day driving impairment at 10 mg in women |
| Zaleplon | ~1 hour | Sleep onset; middle-of-night awakening | Shortest duration. Can be taken if 4+ hours remain. | No benefit for sleep maintenance |
| Eszopiclone | ~6 hours | Onset and maintenance | Only Z-drug approved for both. Bitter taste in up to 34% of patients. | Greater next-day sedation than zolpidem IR |
Complex sleep behaviors (sleepwalking, sleep-driving, activities with no memory of event) — 2019 FDA boxed warning. Risk increased by higher doses, alcohol, and other central nervous system depressants. Previous complex sleep behavior with any sedative-hypnotic: contraindication to use.
| Clinical Situation | Preferred Agent | Rationale |
|---|---|---|
| Sleep-onset insomnia, general adult | Zolpidem IR or zaleplon | Rapid onset, short duration |
| Sleep-maintenance insomnia | Suvorexant or lemborexant | Best evidence for wake-after-sleep-onset reduction |
| Elderly patient | Ramelteon (preferred); lowest-dose Z-drug if needed | No dependence, not on Beers Criteria |
| Substance use disorder history | Ramelteon | Not scheduled; no abuse potential established |
| Sleep-onset and maintenance (combined) | Eszopiclone or dual orexin receptor antagonist | Approved for both complaint types |
| Comorbid depression | Low-dose doxepin (3–6 mg) | Only antidepressant FDA-approved specifically for insomnia |
Suggested References
| Author / Organization | Title | Source |
|---|---|---|
| Katzung BG (ed) | Basic and Clinical Pharmacology, 15th ed. Chapter 22: Sedative-Hypnotic Drugs | McGraw-Hill, 2021 |
| Brunton LL, Knollmann BC (eds) | Goodman and Gilman's The Pharmacological Basis of Therapeutics, 14th ed. Chapter 17: Hypnotics and Sedatives | McGraw-Hill, 2023 |
| Sateia MJ, Buysse DJ, Krystal AD, et al | Clinical practice guideline for the pharmacological treatment of chronic insomnia in adults | J Clin Sleep Med. 2017;13(2):307–349 |
| Sanna E, Busonero F, Talani G, et al | Comparison of the effects of zaleplon, zolpidem, and triazolam at various GABA-A receptor subtypes | Eur J Pharmacol. 2002;451(2):103–110 |
| US Food and Drug Administration | FDA Drug Safety Communication: Risk of next-morning impairment after use of insomnia drugs | FDA. January 10, 2013 |
| Drover DR | Comparative pharmacokinetics and pharmacodynamics of short-acting hypnosedatives: zaleplon, zolpidem and zopiclone | Clin Pharmacokinet. 2004;43(4):227–238 |
| US Food and Drug Administration | FDA Drug Safety Communication: FDA adds boxed warning for risk of serious injuries caused by sleepwalking with certain prescription insomnia medicines | FDA. April 30, 2019 |
| American Geriatrics Society | 2023 updated AGS Beers Criteria for potentially inappropriate medication use in older adults | J Am Geriatr Soc. 2023;71(7):2052–2081 |
| Kato K, Hirai K, Nishiyama K, et al | Neurochemical properties of ramelteon (TAK-375), a selective MT1/MT2 receptor agonist | Neuropharmacology. 2005;48(2):301–310 |
| Sakurai T | The neural circuit of orexin (hypocretin): maintaining sleep and wakefulness | Nat Rev Neurosci. 2007;8(3):171–181 |
| Herring WJ, Connor KM, Ivgy-May N, et al | Suvorexant in patients with insomnia: results from two 3-month randomized controlled clinical trials | Biol Psychiatry. 2016;79(2):136–148 |
| Murphy P, Kumar D, Zammit G, et al | Safety of lemborexant versus placebo and zolpidem: effects on postural stability and cognitive performance in healthy older participants | J Clin Sleep Med. 2020;16(5):765–773 |