Temazepam (anxiolytic): uses, characteristics and adverse effects

The benzodiazepines They are a group of drugs that slow down the central nervous system and decrease neuronal arousal.

Although there are different types, these drugs are used primarily as anxiolytics, hypnotics, and muscle relaxants. Temazepam is an example of a benzodiazepine used to help you fall asleep and reduce nighttime awakenings.

In this article we explain what temazepam is, what are its main characteristics and clinical uses, its mechanism of action, and the effects side effects, interactions and contraindications that we must take into account when using this medicine.

• Related article: "Types of anxiolytics: drugs that fight anxiety"

Temazepam: characteristics and clinical uses

Temazepam is a drug from the group of benzodiazepines used mainly in the treatment of insomnia and severe or disabling sleep disorders. This drug is also used in anxiety disorders, since in addition to having hypnotic effects, it exerts an anxiolytic and sedative action. Its half-life is approximately 10 hours, making it appropriate for treating maintenance insomnia.

This compound was patented in 1962, and marketed for medical use in 1969 under the name "Restoril." In 1982 it was approved by the Food and Drug Administration (FDA), and currently there are several pharmaceutical companies that manufacture it in its generic form.

Studies conducted in sleep laboratories have shown that temazepam decreases dramatically. the number of nocturnal awakenings is significant, although it has a distorting effect on normal patterns of the dream. Typically this medication is administered orally and the effects begin sixty minutes later, lasting up to eight hours in total.

The prescription and consumption of benzodiazepines is widespread in the population, especially among the elderly. And although temazepam is a relatively safe and effective drug, its consumption quickly builds tolerance to its hypnotic and anxiolytic effects, which causes the dose to be increased. Prescribing guidelines typically limit the use of these types of medications to two to four weeks, due to tolerance and dependency issues.

Because benzodiazepines can be abused, their use should be avoided by people in certain high-risk groups, such as people with a history of dependence on alcohol or other drugs, people with emotional problems and patients with mental disorders serious.

Mechanism of action

Temazepam, like many other similar benzodiazepines, acts as a modulator of gamma-aminobutyric acid (GABA) and is capable of causing a variety of effects including: sedation, hypnosis, skeletal muscle relaxation, anticonvulsant activity, and anxiolytic action.

GABA is considered the main inhibitory neurotransmitter in the human body. When this neurotransmitter binds to GABAA receptors found at neuronal synapses, the Chloride ions are conducted through the cell membranes of neurons through an ion channel in the cells. receivers. With sufficient chloride ions, the membrane potentials of associated local neurons are hyperpolarize, making it more difficult or less likely for the potentials of action, resulting in less excitation of neurons.

Although the main pharmacological activity of temazepam is to increase the effect of the neurotransmitter GABA, in animal studies (specifically, in rats) it has also been shown that the drug triggers the release of vasopressin in the paraventricular nucleus of the hypothalamus and decreases the release of adrenocorticotropic hormone under conditions of stress.

Interactions and contraindications

As with other benzodiazepines, temazepam produces central nervous system depressant effects when co-administered. with other medicines that also produce this depressant effect, such as barbiturates, alcohol, opiates, tricyclic antidepressants, non-selective MAO inhibitors, phenothiazines and other antipsychotics, muscle relaxants, antihistamines, and anesthetics.

Administration of theophylline or aminophylline has been shown to reduce the sedative effects of temazepam and other benzodiazepines. Unlike many other benzodiazepines, pharmacokinetic interactions involving cytochrome P450 have not been observed with temazepam.

Furthermore, temazepam does not show a significant interaction with cytochrome CYP3A4 inhibitors, and Oral contraceptives may decrease the effectiveness of this medicine and speed up your half-life elimination. On the other hand, the use of temazepam should be avoided, as far as possible, in people with these conditions:

• Ataxia (inability to coordinate muscle movements)

• Severe hypoventilation

• Severe liver deficiencies, such as hepatitis or cirrhosis.

• Severe kidney problems (eg. ex. dialysis patients)

• Angle closure glaucoma

• Sleep apnea

• Severe depression, especially if accompanied by suicidal tendencies

• Acute intoxication with alcohol and other psychoactive substances

• Myasthenia gravis

• Hypersensitivity or allergy to benzodiazepines

Side effects

The consumption of temazepam is not without possible side effects and adverse reactions.. The most common and shared by the vast majority of benzodiazepines are related to central nervous system depression and include: drowsiness, sedation, drunkenness, dizziness, fatigue, ataxia, headache, lethargy, impaired memory and learning.

There may also be impaired motor functions and coordination, difficulty speaking, decreased speech, physical performance, emotional numbness, decreased alertness, muscle weakness, blurred vision and lack of concentration. Rarely, a state of euphoria has been reported following the use of temazepam. In addition, cases of retrograde amnesia and respiratory depression have been reported in high doses.

In a 2009 meta-analysis a 44% increase was found in the rate of occurrence of mild infections, such as pharyngitis and sinusitis, in people who had taken temazepam or other hypnotic medications compared to those who took a placebo.

Furthermore, hyperhidrosis, hypotension, burning eyes, increased appetite, changes in libido, hallucinations, fainting, nystagmus, vomiting, pruritus, gastrointestinal disorders, nightmares, palpitations and paradoxical reactions such as restlessness, aggression, violence, overstimulation and agitation (in less than 0.5% of cases).

Bibliographic references:

• Mitler, M. M., Mary A. Carskadon, R. L. Phillips, W. R. Sterling, V. P. Zarcone, R. Spiegel Jr, C. Guilleminault, & W. C. Dement. "Hypnotic efficacy of temazepam: a long-term sleep laboratory evaluation." British journal of clinical pharmacology 8, no. Suppl 1 (1979): 63S.

• Ruben, S. M., & Morrison, C. L. (1992). Temazepam misuse in a group of injecting drug users. British Journal of Addiction, 87 (10), 1387-1392.

• Schwarz, H. J. (1979). Pharmacokinetics and metabolism of temazepam in man and several animal species. British journal of clinical pharmacology, 8 (Suppl 1), 23S.