Temazepam
Temazepam is an intermediate-acting benzodiazepine used in adults for the short-term treatment of insomnia. It potentiates GABA-A signalling, with a moderate half-life suited to sleep maintenance and a relevant dependence risk.
- Chemical formula
- C16H13ClN2O2
- CAS number
- 846-50-4
- ATC code
- N05CD07
- Molecular weight
- 300.74 g/mol
- Drug class
- Benzodiazepine hypnotic
- Also known as
- Ro 5-5345, Temazepam
What is it?
Temazepam is a 1,4-benzodiazepine introduced in the 1960s and approved as a hypnotic for the short-term treatment of insomnia. It is supplied as oral capsules and tablets at standard strengths and is dispensed only on prescription. Compared with newer non-benzodiazepine hypnotics, temazepam is a classical benzodiazepine, with the typical class effects on sedation, muscle relaxation and anxiety in addition to sleep induction.
Mechanism of action
Temazepam binds the benzodiazepine site of the GABA-A receptor and allosterically enhances inhibitory chloride conductance. Hyperpolarisation of central nervous system neurons produces sedation, sleep induction, prolongation of total sleep time and a reduction of nocturnal awakenings. The relatively moderate half-life favours sleep maintenance over a single short-acting onset effect.
Pharmacokinetics
Temazepam is well absorbed orally, with peak plasma concentrations reached within 30 minutes to two hours. Plasma protein binding is approximately 96%. The drug is metabolised in the liver by glucuronidation to inactive metabolites, with limited involvement of the cytochrome P450 system. The terminal half-life ranges from 8 to 20 hours, supporting effects throughout the night with potential for some next-day residue. Renal excretion of metabolites is the main elimination pathway.
Indications
Temazepam is approved in adults for the short-term treatment of insomnia, particularly when difficulty maintaining sleep is prominent. According to clinical guidelines, prescription should be limited to the lowest effective dose for the shortest period needed, typically two to four weeks, with periodic reassessment. Temazepam is not indicated for chronic insomnia as a first-line approach, nor for paediatric patients.
Safety profile
Common adverse effects include drowsiness, dizziness, headache and gastrointestinal symptoms. Next-day residual sedation can occur, especially in older adults, and increases the risk of falls and motor vehicle accidents. Tolerance, physical dependence and withdrawal symptoms are documented with chronic use. Combination with alcohol or other CNS depressants increases the risk of severe sedation and respiratory depression. According to the prescribing information, discontinuation should follow a gradual tapering schedule when treatment has been prolonged.
Products containing this ingredient
Frequently asked questions
Is temazepam better for sleep onset or for sleep maintenance? ▾
Temazepam has a moderate half-life of 8 to 20 hours, which is longer than typical sleep-onset Z-drugs and supports sleep maintenance throughout the night. According to the prescribing information, the medication is taken about 30 minutes before bedtime and is most useful when difficulty maintaining sleep or early-morning awakening are prominent. The choice between hypnotics is made by the prescriber based on the type of insomnia and patient profile.
Can temazepam cause next-day sedation? ▾
Yes. Because of its moderate half-life, some residual sedation can persist into the following morning, particularly with higher doses, in older patients or in slow metabolisers. This may impair driving and the operation of machinery. According to the prescribing information, the lowest effective dose should be used and patients should be cautious about activities requiring alertness on the day after treatment.
Is temazepam addictive? ▾
Temazepam, like other benzodiazepines, has a recognised potential for tolerance, physical dependence and withdrawal symptoms with chronic use, and a potential for misuse. The risk increases with higher doses, longer duration of treatment and concurrent substance use. According to the prescribing information, prescription should be limited to short-term use, with gradual tapering at the end of treatment to avoid rebound insomnia and other withdrawal symptoms.
Can temazepam be combined with alcohol or opioids? ▾
No. Combining temazepam with alcohol, opioids or other central nervous system depressants increases the risk of severe sedation, respiratory depression, accidents and overdose. The combination of benzodiazepines and opioids is identified by several public health agencies as a major contributor to overdose mortality. According to the prescribing information, patients should disclose all concomitant medications and avoid alcohol.
What are the main contraindications for temazepam? ▾
Temazepam is contraindicated in known hypersensitivity to benzodiazepines, in severe respiratory insufficiency, in obstructive sleep apnoea, in narrow-angle glaucoma and in severe hepatic impairment. Caution is required in older adults, in patients with substance use disorders and during pregnancy, where benzodiazepines are generally avoided. According to the prescribing information, the medical history must be reviewed by a clinician before any prescription.
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