Pharmacology
Nitrazepam is a nitrobenzodiazepine. It is a 1,4 benzodiazepine, with the chemical name 1,3-Dihydro-7-nitro-5-phenyl-2H-1,4- benzodiazepin-2-one.
It is long acting, is lipophilic and is metabolised hepatically via oxidative pathways. It acts on benzodiazepine receptors in the brain which are associated with the GABA receptors, causing an enhanced binding of GABA (gamma-aminobutyric acid) to GABAA receptors. GABA is a major inhibitory neurotransmitter in the brain, involved in inducing sleepiness, muscular relaxation and control of anxiety and seizures, and slows down the central nervous system. The mechanism of action of nitrazepam is the same as other benzodiazepine drugs and zopiclone. The anticonvulsant properties of nitrazepam and other benzodiazepines may be in part or entirely due to binding to voltage-dependent sodium channels rather than benzodiazepine receptors. Sustained repetitive firing seems to be limited by benzodiazepines effect of slowing recovery of sodium channels from inactivation in mouse spinal cord cell cultures. The muscle relaxant properties of nitrazepam are produced via inhibition of polysynaptic pathways in the spinal cord of decerebrate cats. It is a full agonist of the benzodiazepine receptor. The endogenous opioid system may play a role in some of the pharmacological properties of nitrazepam in rats. Nitrazepam causes a decrease in the cerebral contents of the amino acids glycine and alanine in the mouse brain. The decrease may be due to activation of benzodiazepine receptors. At high doses decreases in histamine turnover occur as a result of nitrazepam's action at the benzodiazepine-GABA receptor complex in mouse brain. Nitrazepam has demonstrated cortisol suppressing properties in man. Nitrazepam is an agonist for both central benzodiazepine receptors, and to the peripheral type benzodiazepine receptors found in rat neuroblastoma cells.
Read more about this topic: Nitrazepam