Triazolam

🧬 Receptor activity

Mechanism of action

Benzodiazepines bind nonspecifically to bezodiazepine receptors BNZ1, which mediates sleep, and BNZ2, which affects affects muscle relaxation, anticonvulsant activity, motor coordination, and memory. As benzodiazepine receptors are thought to be coupled to gamma-aminobutyric acid-A (GABA_A) receptors, this enhances the effects of GABA by increasing GABA affinity for the GABA receptor. Binding of GABA to the site opens the chloride channel, resulting in a hyperpolarized cell membrane that prevents further excitation of the cell.
In animals, benzodiazepines protect against seizures induced by electrical stimulation and by pentylenetetrazol; benzodiazepines appear to act, at least partly, by augmenting presynaptic inhibition. The drugs suppress the spread of seizure activity but do not abolish the abnormal discharge from a focus in experimental models of epilepsy. In usual doses, benzodiazepines appear to have very little effect on the autonomic nervous system, respiration, or the cardiovascular system. /Benzodiazepines/
... /Benzodiazepines/ appear to act at the limbic, thalamic, and hypothalamic levels of the CNS, producing anxiolytic, sedative, hypnotic, skeletal muscle relaxant, and anticonvulsant effects. The effects of benzodiazepines may be mediated through the inhibitory neurotransmitter gamma-aminobutyric acid. Benzodiazepines are capable of producing all levels of CNS depression from mild sedation to hypnosis to coma. /Benzodiazepines/
Anxiolytic and possibly paradoxical CNS stimulatory effects of benzodiazepines are postulated to result from release of previously suppressed responses (disinhibition). After usual doses of benzodiazepines for several days, the drugs cause a moderate decrease in rapid eye movement (REM) sleep. REM rebound does not occur when the drugs are withdrawn. Stage 3 and 4 sleep are markedly reduced by usual doses of the drugs; the clinical importance of these sleep stage alterations has not been established. /Benzodiazepines/
Benzodiazepines appear to produce skeletal muscle relaxation predominantly by inhibiting spinal polysynaptic afferent pathways, but the drugs may also inhibit monosynaptic afferent pathways. The drugs may inhibit monosynaptic and polysynaptic reflexes by acting as inhibitory neuronal transmitters or by blocking exitatory synaptic transmission. The drugs may also directly depress motor nerve and muscle function. /Benzodiazepines/

Pharmacodynamics

A short-acting benzodiazepine used as a hypnotic agent in the treatment of insomnia. Some countries temporarily withdrew triazolam from the market because of concerns about adverse reactions, mostly psychological, associated with higher dose ranges. Its use at lower doses with appropriate care and labeling has been reaffirmed by the FDA and most other countries. Triazolam has a shorter half-life than chlordiazepoxide, flurazepam, and prazepam and does not generate active metabolites.

Pharmacokinetics

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