General Information

Sonata (zaleplon) is a nonbenzodiazepine hypnotic from the pyrazolopyrimidine class.

Sonata is specifically indicated for the short-term treatment of insomnia. 

Sonata is supplied as capsules. The dose of Sonata should be individualized. The recommended dose of Sonata for most nonelderly adults is 10 mg. For certain low weight individuals, 5 mg may be a sufficient dose. Although the risk of certain adverse events associated with the use of Sonata appears to be dose dependent, the 20 mg dose has been shown to be adequately tolerated and may be considered for the occasional patient who does not benefit from a trial of a lower dose. Doses above 20 mg have not been adequately evaluated and are not recommended.

Sonata should be taken immediately before bedtime or after the patient has gone to bed and has experienced difficulty falling asleep. Taking Sonata with or immediately after a heavy, high-fat meal results in slower absorption and would be expected to reduce the effect of Sonata on sleep latency.

Mechanism of Action

While Sonata (zaleplon) is a hypnotic agent with a chemical structure unrelated to benzodiazepines, barbiturates, or other drugs with known hypnotic properties, it interacts with the gamma-aminobutyric acid-benzodiazepine (GABA-BZ) receptor complex. Subunit modulation of the GABA-BZ receptor chloride channel macromolecular complex is hypothesized to be responsible for some of the pharmacological properties of benzodiazepines, which include sedative, anxiolytic, muscle relaxant, and anticonvulsive effects in animal models.

Side Effects

Adverse effects associated with the use of Sonata may include, but are not limited to, the following:

• Headache
• Abdominal pain
• Asthenia
• Nausea
• Dizziness
• Somnolence

The Sonata drug label comes with the following Black Box Warning:

Complex sleep behaviors including sleep-walking, sleep-driving, and engaging in other activities while not fully awake may occur following use of Sonata. Some of these events may result in serious injuries, including death. Discontinue Sonata immediately if a patient experiences a complex sleep behavior.

Clinical Trial Results

Sonata (typically administered in doses of 5 mg, 10 mg, or 20 mg) has been studied in patients with chronic insomnia (n = 3,435) in 12 placebo- and active-drug-controlled trials. Three of the trials were in elderly patients (n = 1,019). It has also been studied in transient insomnia (n = 264).

Transient Insomnia

Normal adults experiencing transient insomnia during the first night in a sleep laboratory were evaluated in a double-blind, parallel-group trial comparing the effects of two doses of Sonata (5 mg and 10 mg) with placebo. Sonata 10 mg, but not 5 mg, was superior to placebo in decreasing latency to persistent sleep (LPS), a polysomnographic measure of time to onset of sleep.

Chronic Insomnia Non-elderly patients:

Adult outpatients with chronic insomnia were evaluated in three double-blind, parallel-group outpatient studies, one of 2 weeks duration and two of 4 weeks duration, that compared the effects of Sonata at doses of 5 mg (in two studies), 10 mg, and 20 mg with placebo on a subjective measure of time to sleep onset (TSO). Sonata 10 mg and 20 mg were consistently superior to placebo for TSO, generally for the full duration of all three studies. Although both doses were effective, the effect was greater and more consistent for the 20-mg dose. The 5-mg dose was less consistently effective than were the 10-mg and 20-mg doses. Sleep latency with Sonata 10 mg and 20 mg was on the order of 10-20 minutes (15%-30%) less than with placebo in these studies.

Adult outpatients with chronic insomnia were evaluated in six double-blind, parallel-group sleep laboratory studies that varied in duration from a single night up to 35 nights. Overall, these studies demonstrated a superiority of Sonata 10 mg and 20 mg over placebo in reducing LPS on the first 2 nights of treatment. At later time points in 5-, 14-, and 28-night studies, a reduction in LPS from baseline was observed for all treatment groups, including the placebo group, and thus, a significant difference between Sonata and placebo was not seen beyond 2 nights. In a 35-night study, Sonata 10 mg was significantly more effective than placebo in reducing LPS at the primary efficacy endpoint on nights 29 and 30.

Chronic Insomnia Elderly patients:

Elderly outpatients with chronic insomnia were evaluated in two 2-week, double-blind, parallel group outpatient studies that compared the effects of Sonata 5 mg and 10 mg with placebo on a subjective measure of time to sleep onset (TSO). Sonata at both doses was superior to placebo on TSO, generally for the full duration of both studies, with an effect size generally similar to that seen in younger persons. The 10-mg dose tended to have a greater effect in reducing TSO. Elderly outpatients with chronic insomnia were also evaluated in a 2-night sleep laboratory study involving doses of 5 mg and 10 mg. Both 5-mg and 10-mg doses of Sonata were superior to placebo in reducing latency to persistent sleep (LPS). Generally in these studies, there was a slight increase in sleep duration, compared to baseline, for all treatment groups, including placebo, and thus, a significant difference from placebo on sleep duration was not demonstrated.