Estazolam
From Wikipedia, the free encyclopedia
 |
|
 |
|
|
Estazolam
|
|
| Systematic (IUPAC) name | |
| 8-Chloro-6-phenyl- 4H-1,2,4-triazolo(4,3-a)- 1,4-benzodiazepine |
|
| Identifiers | |
| CAS number | |
| ATC code | N05 |
| PubChem | |
| DrugBank | |
| Chemical data | |
| Formula | C16H11ClN4 |
| Mol. mass | 294.7 |
| Pharmacokinetic data | |
| Bioavailability | 93% |
| Metabolism | Hepatic |
| Half life | 10-24 hours |
| Excretion | Renal |
| Therapeutic considerations | |
| Pregnancy cat. |
? (USA) |
| Legal status | |
| Routes | Oral |
Estazolam (marketed under the brand names ProSom, Eurodin) is a drug which is a benzodiazepine derivative. It possesses anxiolytic, anticonvulsant, sedative and skeletal muscle relaxant properties. Estazolam is an intermediate-acting oral benzodiazepine.
It is commonly prescribed for short-term treatment of insomnia.
Contents |
[edit] Pharmacology
Estazolam is classed as a "triazolo" benzodiazepine drug.[1] An animal study demonstrated that estazolam induces a drowsy pattern of spontaneous EEG including high voltage slow waves and spindle bursts increase in the cortex and amygdala, while the hippocampal theta rhythm is desynchronized. Also low voltage fast waves occur particularly in the cortical EEG. The EEG arousal response to auditory stimulation and to electric stimulation of the mesencephalic reticular formation, posterior hypothalamus and centromedian thalamus is significantly suppressed. The photic driving response elicited by a flash light in the visual cortex is significantly suppressed by estazolam.[2] Estazolam at high doses decreases histamine turnover via it's action at the benzodiazepine-GABA receptor complex.[3]
Estazolam and other benzodiazepines may influence neurosteroid metabolism which in turn may influence the functions of the brain and reproductive system. The pharmacological actions of benzodiazepines at the GABAa receptor are similar to those of neurosteroids. Neuroactive steroids are positive allosteric modulators of the GABAa receptor, enhancing GABA function. Many hypnotic benzodiazepines (nimetazepam, temazepam, estazolam, flunitrazepam and nitrazepam) potently inhibit the enzymes involved in the metabolism of neurosteroids. Long-term administration of benzodiazepines may influence the concentrations of endogenous neurosteroids, and thereby would modulate the emotional state. Factors which effects benzodiazepines ability to alter neurosteroid levels depend on the molecular make up of the individual benzodiazepine. Presence of a substituent at N1 position of the diazepine ring and/or the chloro or nitro group at position 7 of the benzene ring contribute to potent inhibition of the isoenzymes, and in turn a bromo group at position 7 (for bromazepam) and additional substituents (3-hydroxy group for oxazepam and tetrahydroxazole ring for cloxazolam and oxazolam) decrease the inhibitory potency.[4]
[edit] Elderly
An extensive review of the medical literature regarding the management of insomnia and the elderly found that there is considerable evidence of the effectiveness and durability of non-drug treatments for insomnia in adults of all ages and that these interventions are underutilized. Compared with the benzodiazepines including estazolam, the nonbenzodiazepine sedative-hypnotics appeared to offer few, if any, significant clinical advantages in efficacy or tolerability in elderly persons. It was found that newer agents with novel mechanisms of action and improved safety profiles, such as the melatonin agonists, hold promise for the management of chronic insomnia in elderly people. Long-term use of sedative-hypnotics for insomnia lacks an evidence base and has traditionally been discouraged for reasons that include concerns about such potential adverse drug effects as cognitive impairment (anterograde amnesia), daytime sedation, motor incoordination, and increased risk of motor vehicle accidents and falls. In addition, the effectiveness and safety of long-term use of these agents remain to be determined. It was concluded that more research is needed to evaluate the long-term effects of treatment and the most appropriate management strategy for elderly persons with chronic insomnia.[5]
[edit] Abuse
Estazolam became notorious in 1998 when a large amount of a 'herbal sleeping mix' called Sleeping Buddha was recalled from the shelves after the FDA discovered that it contained estazolam (as well as some heavy metal salts).[citation needed]
[edit] See also
[edit] References
- ^ Braestrup C; Squires RF. (Apr 1978). "Pharmacological characterization of benzodiazepine receptors in the brain.". Eur J Pharmacol 48 (3): 263–70. doi:. PMID 639854.
- ^ Watanabe S; Ohta H, Sakurai Y, Takao K, Ueki S. (Jul 1986). "[Electroencephalographic effects of 450191-S and its metabolites in rabbits with chronic electrode implants]". Nippon Yakurigaku Zasshi. 88 (1): 19–32. PMID 3758874.
- ^ Oishi R; Nishibori M, Itoh Y, Saeki K. (27). "Diazepam-induced decrease in histamine turnover in mouse brain.". Eur J Pharmacol. 124 (3): 337–42. doi:. PMID 3089825.
- ^ Usami N; Yamamoto T, Shintani S, Ishikura S, Higaki Y, Katagiri Y, Hara A. (Apr 2002). "Substrate specificity of human 3(20)alpha-hydroxysteroid dehydrogenase for neurosteroids and its inhibition by benzodiazepines." (pdf). Biol Pharm Bull. 25 (4): 441–5. doi:. PMID 11995921.
- ^ Bain KT (Jun 2006). "Management of chronic insomnia in elderly persons". Am J Geriatr Pharmacother 4 (2): 168–92. doi:. PMID 16860264.
[edit] External links
- Flash animation about how estazolam works (mechanism of action)
- Rx-List - Estazolam
- Inchem - Estazolam
|
|||||||||||||||||||||||||||||
 |
This pharmacology-related article is a stub. You can help Wikipedia by expanding it. |
