Premazepam

Premazepam

Systematic (IUPAC) name
6,7-dimethyl-5-phenyl-1,3-dihydropyrrolo[3,4-e][1,4]diazepin-2-one
Pharmacokinetic data
Metabolism	Hepatic
Biological half-life	10–13 hours
Excretion	Renal
Identifiers
CAS Number	57435-86-6
PubChem	CID 72104
ChemSpider	65088
UNII	OI7443PDLB
ChEMBL	CHEMBL2104741
Chemical data
Formula	C15H15N3O
Molar mass	253.30 g/mol
SMILES Cc1c2c(cn1C)NC(=O)CN=C2c3ccccc3
InChI InChI=1S/C15H15N3O/c1-10-14-12(9-18(10)2)17-13(19)8-16-15(14)11-6-4-3-5-7-11/h3-7,9H,8H2,1-2H3,(H,17,19) Key:CNWSHOJSFGGNLC-UHFFFAOYSA-N
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Premazepam is a benzodiazepine derivative.^[1] It is a partial agonist of benzodiazepine receptors and was shown in 1984 to possess both anxiolytic and sedative properties in humans but was never marketed.

Properties

The initial doses of premazepam given to human test subjects demonstrated similar psychological test results to those produced by diazepam. It was also demonstrated that initial dosing with premazepam produces similar sedative effects as compared with diazepam, although psychomotor impairments are greater with premazepam than with diazepam after initial dosing. However, with repeated dosing for more than one day premazepam causes less sedation and less psychomotor impairment than diazepam. Premazepam possesses sedative and anxiolytic properties. Premazepam produces more slow wave and less fast wave EEG changes than diazepam. Tests have shown that 7.5 mg of premazepam is approximately equivalent to 5 mg of diazepam.^[2]

Pharmacology

Premazepam is a pyrrolodiazepine benzodiazepine and acts as a partial agonist at benzodiazepine receptors. The mean time taken to reach peak plasma levels is 2 hours and the mean half life of premazepam in humans is 11.5 hours. About 90% of the drug is excreted in unchanged form. Of the remaining 10% of the drug none of the metabolites showed any pharmacological activity. Thus premazepam produces no active metabolites in humans.^[3][4]

See also

• Benzodiazepine
• Benzodiazepine dependence
• Benzodiazepine withdrawal syndrome
• Long-term effects of benzodiazepines

References

1. Assandri A; Barone D; Ferrari P; Perazzi A; Ripamonti A; Tuan G; Zerilli LF (Mar–Apr 1984). "Metabolic fate of premazepam, a new anti-anxiety drug, in the rat and the dog". Drug Metab Dispos 12 (2): 257–63. PMID 6144494.
2. Golombok S; Lader M (August 1984). "The psychopharmacological effects of premazepam, diazepam and placebo in healthy human subjects". Br J Clin Pharmacol 18 (2): 127–33. doi:10.1111/j.1365-2125.1984.tb02444.x. PMC 1463527. PMID 6148956.
3. Vitiello B; Buniva G; Bernareggi A; Assandri A; Perazzi A; Fuccella LM; Palumbo R (May 1984). "Pharmacokinetics and metabolism of premazepam, a new potential anxiolytic, in humans". Int J Clin Pharmacol Ther Toxicol 22 (5): 273–7. PMID 6146571.
4. Mennini T; Barone D; Gobbi M (1985). "In vivo interaction of premazepam with benzodiazepine receptors: relation to its pharmacological effects". Psychopharmacology (Berl) 86 (4): 464–7. doi:10.1007/BF00427909. PMID 2863844.