Temazepam is an orally available benzodiazepine used in the therapy of insomnia. As with most benzodiazepines, temazepam therapy has not been associated with serum aminotransferase or alkaline phosphatase elevations, and clinically apparent liver injury from temazepam has not been reported and must be very rare, if it occurs at all.
Temazepam (tem az' e pam) is a benzodiazepine that is widely used as a sleeping aid in the therapy of insomnia. The soporific activity of the benzodiazepines is mediated by their ability to enhance gamma-aminobutyric acid (GABA) mediated inhibition of synaptic transmission through binding to the GABA A receptor. Temazepam was approved in the United States in 1981, and currently more than 8 million prescriptions are filled yearly. Current indications are for the short term treatment of insomnia. Temazepam is available in capsules of 7.5, 15, 22 and 30 mg in several generic forms and under the brand name Restoril. The recommended initial dose for insomnia is 7.5 mg before bedtime, increasing as needed to a maximum dose of 30 mg. The most common side effects of temazepam are dose related and include daytime drowsiness, lethargy, ataxia, dysarthria and dizziness. Tolerance develops to these side effects, but tolerance may also develop to the effects on insomnia.
Temazepam, like other benzodiazepines, is rarely associated with serum ALT elevations, and clinically apparent liver injury from temazepam is extremely rare, if it occurs at all. There have been no case reports of symptomatic, acute liver injury from temazepam. Cases of clinically apparent liver injury have been reported with other benzodiazepines including alprazolam, chlordiazepoxide, clonazepam, diazepam, flurazepam and triazolam. The clinical pattern of acute liver injury from benzodiazepines is typically cholestatic and mild-to-moderate in severity with a latency of 1 to 6 months. Fever and rash are uncommon as is autoantibody formation.
Mechanism of Injury
Temazepam is metabolized by the liver to inactive metabolites. Liver injury from benzodiazepines is probably due to the toxic effects of a rarely produced intermediate metabolite.
Outcome and Management
The case reports of hepatic injury due to benzodiazepines were followed by prompt and complete recovery upon stopping the medication, without evidence of residual or chronic injury. No cases of acute liver failure or chronic liver injury due to temazepam have been described. There is no information about cross reactivity with other benzodiazepines, but some degree of cross sensitivity may occur.
Drug Class: Sedatives and Hypnotics, Benzodiazepines
Temazepam – Generic, Restoril®
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