Pharmacokinetic data
Elimination half-life10–13 hours
  • 6,7-Dimethyl-5-phenyl-1,3-dihydropyrrolo[3,4-e][1,4]diazepin-2-one
CAS Number
PubChem CID
CompTox Dashboard (EPA)
Chemical and physical data
Molar mass253.305 g·mol−1
3D model (JSmol)
  • Cc1c2c(cn1C)NC(=O)CN=C2c3ccccc3
  • 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) ☒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.


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]


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


  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 Metabolism and Disposition. 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". British Journal of Clinical Pharmacology. 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". International Journal of Clinical Pharmacology, Therapy, and Toxicology. 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. 86 (4): 464–7. doi:10.1007/BF00427909. PMID 2863844. S2CID 9882896.