Zaleplon is a sedative/hypnotic, mainly used for insomnia. It is known as a non-benzodiazepine hypnotic. Zaleplon interacts with the GABA receptor complex and shares some of the pharmacological properties of the benzodiazepines.
Zaleplon is a non-benzodiazepine hypnotic from the pyrazolopyrimidine class and is indicated for the short-term treatment of insomnia. While 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 (GABABZ) receptor complex. Subunit modulation of the GABABZ 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.
Zaleplon exerts its action through subunit modulation of the GABABZ receptor chloride channel macromolecular complex. Zaleplon also binds selectively to the brain omega-1 receptor located on the alpha subunit of the GABA-A/chloride ion channel receptor complex and potentiates t-butyl-bicyclophosphorothionate (TBPS) binding.
Absorption Zaleplon is rapidly and almost completely absorbed following oral administration.
Approximately 60% (in vitro plasma protein binding).
Zaleplon is primarily metabolized by aldehyde oxidase.
Zaleplon is metabolized primarily by the liver and undergoes significant presystemic metabolism. After oral administration, Zaleplon is extensively metabolized, with less than 1% of the dose excreted unchanged in urine. Renal excretion of unchanged Zaleplon accounts for less than 1% of the administered dose.
Side effects include abdominal pain, amnesia, dizziness, drowsiness, eye pain, headache, memory loss, menstrual pain, nausea, sleepiness, tingling, and weakness.
Avoid alcohol. Ingesting alcohol may increase the CNS depressant effects of Zaleplon.
Do not take with or immediately after a high-fat meal. The effects of Zaleplon are reduced when taken with a high-fat meal.
Zaleplon is indicated for the short-term treatment of insomnia. Zaleplon has been shown to decrease the time to sleep onset for up to 30 days in controlled clinical studies (see Clinical Trials under CLINICAL PHARMACOLOGY).
DOSAGE AND ADMINISTRATION
The dose of Zaleplon should be individualized. The recommended dose of Zaleplon 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 Zaleplon 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.
Zaleplon should be taken immediately before bedtime or after the patient has gone to bed and has experienced difficulty falling asleep (see PRECAUTIONS). Taking Zaleplon with or immediately after a heavy, high-fat meal results in slower absorption and would be expected to reduce the effect of Zaleplon on sleep latency.
Elderly patients and debilitated patients appear to be more sensitive to the effects of hypnotics, and respond to 5 mg of Zaleplon. The recommended dose for these patients is therefore 5 mg. Doses over 10 mg are not recommended.
