Eszopiclone

Eszopiclone is a nonbenzodiazepine hypnotic used in the treatment of insomnia. It belongs to the cyclopyrrolone class and acts as a positive allosteric modulator of the GABA-A receptor, producing sedative effects that help initiation and maintenance of sleep. It is marketed in the United States under the brand name Lunesta and is also available as a generic medication.

Indications and dosage: Eszopiclone is indicated for adults with insomnia characterized by difficulty with sleep onset and/or sleep maintenance. It is taken as a single dose at bedtime. The usual adult dose is 2 mg; it may be increased to 3 mg if needed. In older adults or those with hepatic impairment, a 1 mg dose is recommended. The maximum recommended dose is 3 mg.

Pharmacology and pharmacokinetics: Eszopiclone is rapidly absorbed with a half-life of about 6 hours in healthy adults, longer in the elderly. It is primarily metabolized by liver enzymes, notably CYP3A4, with additional involvement of other cytochrome P450s, and excreted as metabolites. Drug interactions with strong CYP3A inhibitors or inducers can alter exposure. Concomitant use with alcohol or other central nervous system depressants is discouraged.

Safety and contraindications: Eszopiclone is contraindicated in hypersensitivity to the drug and in individuals with sleep apnea or severe hepatic impairment. Pregnancy category C; use during pregnancy or lactation only if the potential benefit justifies the risk. Caution in elderly patients due to increased sensitivity to adverse effects, including next-day impairment, falls, and confusion. Rare but serious adverse effects include complex sleep-related behaviors such as sleep-walking.

Adverse effects: Common adverse effects include somnolence, dizziness, unpleasant metallic or bitter taste, dry mouth, fatigue, and headache.