Temazepam versus Diazepam
Temazepam and diazepam are both benzodiazepine hypnotics with a sedative effect, meaning they are central nervous system relaxants that mimic the activity of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA), thereby reducing neuronal activation.
These drugs can be used for various purposes, such as:
- inducing profound sedation,
- treating seizures and sleep disorders,
- reducing sleep latency,
- and treating symptoms of alcohol withdrawal syndrome.
Additionally, benzodiazepines are also skeletal muscle relaxants, capable of treating muscle spasms [1, 2]. Although both temazepam and diazepam belong to the same class of drugs, they have slightly different properties, uses, and risks. This blog will discuss the similarities and differences between these two benzodiazepines.
Temazepam vs Diazepam: Indications
Temazepam increases sleepiness and is primarily used to reduce sleep latency in sleep problems such as insomnia. It is also used off-label for jetlag adaptation.
Diazepam, on the other hand, is used for a wider range of conditions, including anxiety disorders, muscle spasms, and alcohol withdrawal symptoms.
Both drugs can also be used for sedation in minor surgeries and gastrointestinal endoscopies. Temazepam should only be used for short periods of up to 10 days at a daily dose of 15-30 mg. Diazepam can be taken over longer periods, but the daily dose should not exceed 10 mg [1, 2].
Which one is better?
There is conflicting evidence regarding the superiority of diazepam and temazepam, particularly for endoscopy and minor surgeries [3, 4]. The efficacy likely depends on the mode of administration.
Intravenous administration of the drug can have a quicker and bigger effect but also a higher risk of side effects like amnesia, the medical term for forgetting [3].
Only diazepam can be administered intravenously, whereas temazepam is only available orally [1, 2]. Temazepam is only approved for treating sleep problems, whereas diazepam is the first-choice benzodiazepine for anxiety, alcohol withdrawal, muscle spasms, and epilepsy.
Pharmacokinetics
Temazepam has a shorter half-life of around 8 to 14.7 hours, compared to the half-life of diazepam, which is 48 hours [5, 6]. Both drugs reach their peak concentrations between 1-2 hours after administration [1, 2]. The shorter half-life of temazepam can result in less daytime drowsiness and lower hangover effects, especially at doses of 15 to 30 mg [6, 7]. In contrast, the longer half-life of diazepam can be helpful for purposes where a longer period of mild sedation is required, such as anxiety.
Both drugs are metabolized in the liver and excreted via the kidneys. The diazepam urine detection time can be up to 100 hours after administration. Temazepam, in contrast, is 80% eliminated by the kidneys and the remaining via feces, indicating a bimodal elimination pattern with a half-life of about 9 hours corresponding to the second phase of elimination [8]. These considerations are important in clinical pharmacology when deciding which benzodiazepine to use.
Temazepam vs Diazepam: Toxicity and Side Effects
Temazepam has become a frequently abused drug in the United States, leading it to be classed as a Schedule IV drug by the FDA [1]. One study found that an overdose of temazepam is more likely to lead to coma compared to other benzodiazepines, particularly due to its pharmacokinetic profile [9]. Diazepam, on the other hand, belongs to the least toxic benzodiazepines, requiring 9 times as much diazepam compared to other drugs to cause significant harm [1]. Hepatic impairment is a likely effect of overdosing on either drug, as both are eliminated through the kidneys.
Side effects between temazepam and diazepam are comparable. A common side effect is benzodiazepine withdrawal, which can include symptoms similar to alcohol withdrawal, such as irritability, trouble sleeping, and anxiety [10]. Additional common side effects include trouble breathing and related respiratory problems, dizziness, brain fog, mental health symptoms including depression and vivid dreams, and impaired coordination [1]. Due to temazepam's short half-life, post-drug hangovers were only reported in 7% of participants. In diazepam, the side effects are likely to last longer.
Drug Interactions: Temazepam vs Diazepam
There are critical drug interactions to be aware of when using prescription drugs such as temazepam and diazepam. Opioids, which are CNS depressants such as naloxone and morphine used for moderate to severe pain, must not be taken with temazepam, as there is an increased risk of respiratory depression, coma, and possibly fatal outcomes.
It is also advised to avoid alcohol, as alcohol is also a CNS depressant and can produce a similar sedative effect to 30 mg of temazepam. These disturbances are exaggerated when taking benzodiazepines and alcohol together, leading to exacerbated side effects of respiratory depression and even coma.
Diazepam has fewer severe drug interactions than temazepam. Taking fluoxetine and similar CYP3A4 inhibitors can increase diazepam levels, while taking St. John's Wort, carbamazepine, topiramate, phenytoin, rifampin, or barbiturates can reduce diazepam levels in the system. Make sure to inform your healthcare provider of all supplements you are taking if you are prescribed benzodiazepines.
Summary: Temazepam vs Diazepam
To summarize, temazepam and diazepam are both benzodiazepine prescription drugs that can be used to induce sedation for sleep problems or minor surgeries. Diazepam has additional indications, a longer half-life, and lower toxicity, whereas temazepam is eliminated more quickly but also has a higher risk of overdose and toxicity. Always consult your healthcare provider about which drug you should be taking and avoid any recreational use of benzodiazepines due to their high risks for drug abuse and fatal side effects.