Products
Zaleplon was commercially available in capsule form (Sonata, 5 mg, 10 mg). It was approved in many countries in 1999. It was discontinued from distribution in April 2013.
Structure and properties
Zaleplon (C17H15N5O, Mr = 305.3 g/mol) is a pyrazolopyrimidine and exists as a white powder that is practically insoluble in water. It is structurally distinct from other sleep aids such as the benzodiazepines and is one of the so-called Z-drugs.
Effects
Zaleplon (ATC N05CF03) is sleep-inducing. It binds to the GABAA receptor in the central nervous system and potentiates the effects of the inhibitory neurotransmitter GABA. Its half-life is short, approximately 1 hour. Therefore, it was approved in many countries for the treatment of sleep onset rather than sleep maintenance disorders.
Indications
For the short-term treatment of insomnia.
Dosage
According to the drug label. Zaleplon is taken immediately before bedtime.
Contraindications
- Hypersensitivity
- Hepatic insufficiency
- Sleep apnea syndrome
- Myasthenia gravis
- Severe respiratory failure
- Children and adolescents
- Alcohol and drug addiction
Full precautions can be found in the drug label.
Interactions
Zaleplon is metabolized by CYP3A4 and has a high first-pass metabolism. Corresponding drug-drug interactions are possible. Central depressant drugs and alcohol may potentiate effects.
Adverse effects
The most common adverse effects include amnesia, sensory disturbances, drowsiness, and menstrual cramps. Zaleplon can cause dependence and withdrawal symptoms, so it should only be used for short periods of time. Other side effects include paradoxical and psychiatric disorders, visual disturbances, elevated liver enzymes, and digestive disturbances.