Zaleplon is a newer non-benzodiazepine hypnotic from the pyrazolopyrimidine class. So, its chemical structure is unrelated to benzodiazepines, barbiturates, or other drugs with known hypnotic properties. It interacts with the gamma aminobutyric acid-benzodiazepine (GABA-BZ) receptor complex.

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 trials.

The dose of Zaleplon should be individualized. The recommended dose of Zaleplon for most non elderly 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 occasional patient who does not benefit from a trial of lower dose. Dosage above 20 mg has not been adequately evaluated and is not recommended.

Zaleplon should be taken immediately before bedtime. 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 hypnotic, and respond to 5 mg of Zaleplon. The recommended dose for these patients is therefore 5 mg, doses over 10 mg are not recommended.

For patients with mild to moderate renal impairment, no dose adjustment is necessary.

An initial dose of 5 mg should be given to patients concomitantly taking Cimetidine because Zaleplon clearance is reduced in this population.

Pediatric use: The safety and effectiveness of Zaleplon in pediatric patients have not been established.

Zaleplon is contraindicated in patients with known hypersensitivity to any of its components.

Side effects of Zaleplon appear to be dose related. So, it is important to use the lowest possible effective dose, specially in the elderly. The side effects are usually mild and transient, the most common are diarrhoea, nausea, vomiting, vertigo, headache, asthenia, nightmare etc.

Timing of drug administration: Zaleplon should be taken immediately before bedtime or after the patient has gone to bed.

Use in the elderly and/or debilitated patients: Impaired motor and/or cognitive performance after repeated exposure or unusual sensitivity to sedative/hypnotic drugs is a concern in the treatment of elderly and/or debilitated patients. A dose of 5 mg is recommended for elderly patients to decrease the possibility of side effects. Elderly and/or debilitated patients should be monitored closely.

Use in patients with concomitant illness: Zaleplon should be used with caution in patients with diseases or conditions that could affect metabolism or haemodynamic responses. Although preliminary studies did not reveal respiratory depressant effects at hypnotic doses of Zaleplon in normal subjects, caution should be observed if Zaleplon is prescribed to patients with compromised respiratory function, because sedative/hypnotic have the capacity to depress respiratory drive. However, patients with compromised respiration due to preexisting illness should be monitored carefully. The dose of Zaleplon should be reduced to 5 mg in patients with mild to moderate hepatic impairment. It is not recommended for use in patients with severe hepatic impairment.

Renal impairment patients: No dose adjustment is necessary in patients with mild to moderate renal impairment. Zaleplon has not been adequately studied in patients with severe renal impairment.

Use in patients with depression: As with other sedative or hypnotic drugs, Zaleplon should be administered with caution to patients exhibiting signs or symptoms of depression

Pregnancy & Lactation

Pregnancy: There are no studies of Zaleplon in pregnant women; therefore, it is not recommended for use in women during pregnancy. Zaleplon has no established use in labour and delivery.

Lactation: A study in lactating mothers indicated that the clearance and half-life of Zaleplon is similar to that in young normal subjects. A small amount of Zaleplon is excreted in breast milk, with the highest excreted amount occurring during a feeding at approximately 1 hour after Zaleplon administration. Since the small amount of the drug from breast milk may result in potentially important concentrations in infants, and because the effects of Zaleplon on a nursing infant are not known, it is not recommended in nursing mothers.