Temazepam

BRAND NAMES

Restoril, Euhypnos, Normison, Norkotral, Nortem, Remestan, Restoril, Temaze, and Temtabs. Available as oral capsules and, in some regions, oral solutions. It is intended for short-term treatment of insomnia, usually for a duration of 7 to 10 days.

MECHANISM OF ACTION

Temazepam is a central nervous system (CNS) depressant that works by enhancing the effects of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA). This action reduces neuronal excitability, leading to its characteristic sedative, hypnotic, anxiolytic (anti-anxiety), and muscle-relaxant effects. 

PHARMACOKINETICS

Absorption

Temazepam is rapidly and effectively absorbed following oral administration, with peak plasma concentrations typically occurring around 1.5 hours after dosing. Its absorption is influenced by the drug's formulation and the time of day it is taken, though the overall bioavailability remains high. 

Distribution

Temazepam has a reported volume of distribution ranging from 1.3 to 1.5 L/kg.

Metabolism

Temazepam is metabolized in the liver primarily through direct glucuronide conjugation into inactive metabolites, which are then excreted via the kidneys. This metabolic pathway is advantageous because it is not significantly affected by liver cytochrome P450 (CYP) enzymes, meaning fewer drug-drug interactions occur compared to other benzodiazepines. 

Excretion

Around 80% to 90% of a single temazepam dose is excreted in the urine, primarily as its O-conjugated metabolite, while roughly 3% to 13% is eliminated via the feces.

PHARMACODYNAMICS

Temazepam is a central nervous system (CNS) depressant that works by enhancing the effects of the neurotransmitter gamma-aminobutyric acid (GABA), which results in sedation, hypnosis, and muscle relaxation. Temazepam is a central nervous system depressant that works by enhancing the effects of the calming neurotransmitter gamma-aminobutyric acid (GABA). It binds to specific receptors on GABA-A receptor subtypes, increasing chloride ion influx and hyperpolarizing neurons, which reduces their excitability. This mechanism produces its primary effects, including sedation, hypnosis, muscle relaxation, and anxiety reduction.

ADMINISTRATION

Temazepam is a sedative-hypnotic medication used for the short-term treatment of insomnia and is available in both oral capsule and liquid formulations. It should be taken right before you go to bed and only when you have a full 7 to 8 hours available for sleep.

DOSAGE AND STRENGTH

Temazepam is mainly available as oral capsules but can also be compounded into various other dosage forms such as oral solutions, suppositories, and micro-enemas, with strengths of 7.5 mg, 15 mg, 22.5 mg, and 30 mg.

In the United Kingdom, temazepam may also be available as 10 mg and 20 mg tablets and as a 10 mg/5 ml liquid. 

DRUG INTERACTIONS

Temazepam has significant interactions with a wide variety of substances, particularly other central nervous system (CNS) depressants like alcohol and opioids. Combining temazepam with these and other sedating medications can lead to dangerous additive effects, including severe drowsiness, respiratory depression, coma, and even death. 

FOOD INTERACTIONS

There are no significant interactions between temazepam and food, and it can be taken with or without a meal. However, consuming a fatty meal may slow down the drug's absorption, potentially delaying its sedative effects. While food interactions are not a major concern, it is crucial to avoid alcohol, as it can cause severe drowsiness and dangerous breathing problems. Grapefruit and grapefruit juice can also increase the drug's concentration in the blood, enhancing its effects. 

CONTRAINDICATIONS

Temazepam should not be used by patients who are hypersensitive or allergic to it or to other benzodiazepines. It is also contraindicated in pregnancy and carries special warnings for use with opioids and in patients with certain medical conditions. 

SIDE EFFECTS

• Next-day drowsiness.

• Dizziness and unsteadiness.

• Abnormal thoughts and behavior.

• "Sleep-driving" and other complex behaviors.

• Worsening depression and suicidal thoughts.

• Severe allergic reaction.

• Dependence and withdrawal.

• Memory problems.

• difficulty peeing or peeing less than usual.

OVER DOSE

A temazepam overdose is a medical emergency that can be fatal, especially when combined with other central nervous system (CNS) depressants like alcohol or opioids. An overdose intensifies the drug's sedative effects, leading to loss of consciousness, slowed breathing, and potentially, death.

TOXICITY

Temazepam toxicity, primarily from overdose, can lead to severe central nervous system (CNS) depression, respiratory failure, and death. The risk of toxicity is significantly increased by mixing temazepam with other CNS depressants, particularly alcohol and opioids.