Zaleplons

Zaleplon is a sedative-hypnotic medication in the nonbenzodiazepine class, often referred to as a z-drug. It is approved for the short-term treatment of insomnia in adults, particularly when difficulty initiating sleep is the primary symptom. It is not generally used for sleep maintenance or middle-of-the-night awakenings due to its very short duration of action.

Pharmacology and effects: Zaleplon binds selectively to the GABA-A receptor at the alpha-1 subunit, producing hypnotic effects with minimal impact on sleep architecture. It has a rapid onset of action and a short half-life, which can reduce the risk of next-day sedation relative to longer-acting hypnotics. It is intended to help with sleep initiation rather than sustaining sleep through the night.

Pharmacokinetics and dosing: After oral administration, zaleplon typically begins working within 15 to 30 minutes on an empty stomach; food can delay absorption. The usual adult dose is 10 mg at bedtime, with 5 mg available for older adults or debilitated patients; the dose should not exceed 20 mg. It is metabolized primarily in the liver by aldehyde oxidase, with minimal involvement of cytochrome P450 enzymes, and has no clinically significant active metabolites. Elimination is rapid.

Safety and considerations: Common adverse effects include dizziness, drowsiness, headache, and nausea. There is a potential for next-day impairment, especially at higher doses or when combined with alcohol or other CNS depressants. Rare but serious risks include complex sleep-related behaviors. Zaleplon should be avoided in patients with hypersensitivity and used cautiously in hepatic impairment and pregnancy.

Regulatory status: Zaleplon is a Schedule IV controlled substance in the United States and is available by prescription for short-term use, typically a few weeks.