Clinical data
Trade namesTelazol (in combination with tiletamine)
AHFS/Drugs.comInternational Drug Names
ATC code
  • none
Legal status
Legal status
  • AU: S4 (Prescription only)
  • 4-(2-fluorophenyl)-1,3,8-trimethyl-6H-pyrazolo[3,4-e][1,4]diazepin-7-one
CAS Number
PubChem CID
CompTox Dashboard (EPA)
ECHA InfoCard100.118.306 Edit this at Wikidata
Chemical and physical data
Molar mass286.310 g·mol−1
3D model (JSmol)
  • FC1=CC=CC=C1C2=NCC(N(C)C3=C2C(C)=NN3C)=O
  • InChI=1S/C15H15FN4O/c1-9-13-14(10-6-4-5-7-11(10)16)17-8-12(21)19(2)15(13)20(3)18-9/h4-7H,8H2,1-3H3 checkY

Zolazepam[1] (Flupyrazapon) is a pyrazolodiazepinone derivative structurally related to the benzodiazepine drugs, which is used as an anaesthetic for a wide range of animals in veterinary medicine. Zolazepam is usually administered in combination with other drugs such as the NMDA antagonist tiletamine or the α2 adrenergic receptor agonist xylazine, depending on what purpose it is being used for. It is around four times the potency of diazepam (0.32 mg/kg versus 1.2 mg/kg in animal models) but it is both water-soluble and un-ionized at physiological pH meaning that its onset is very fast.[2]

Zolazepam was developed by Horace A. de Wald and Donald E. Butler for Parke-Davis[3] and was the result of a very detailed analysis of the benzodiazepine structure (U.S. Patent 3,558,605 filed in 1969).

Zolazepam, in combination with tiletamine, has been used in the tranquilization of wild animals, such as gorillas and polar bears, and has been found to be superior to ketamine because of reduced side-effects.[4][5] A 1:1 mixture of zolazepam and tiletamine is sold under the names Telazol and Zoletil.

See also


  1. ^ US 3879535, Stoliker, Harry E., "Anesthetic compositions and methods of use", published 1975-04-22, assigned to Parke, Davis & Co. 
  2. ^ DeWald HA, Lobbestael S, Butler DE (December 1977). "Pyrazolodiazepines. 2. 4-Aryl-1,3-dialkyl-6,8-dihydropyrazolo[3,4-e] [1,4]diazepin-7(1H)-ones as antianxiety and anticonvulsant agents". Journal of Medicinal Chemistry. 20 (12): 1562–9. doi:10.1021/jm00222a005. PMID 22748.
  3. ^ DE 2023453, DeWald, Horace Albert & Butler, Donald Eugene, "Pyrazolo[3,4-e],[1,4]diazepin-7(1H)-on Verbindungen und ihre pharmazeutisch zulässigen Salze [Pyrazolo[3,4-e],[1.4]diazepin-7(lH)-one compounds and their pharmaceutically acceptable salts]", published 1970-11-19, assigned to Parke, Davis & Co. 
  4. ^ Sleeman JM, Cameron K, Mudakikwa AB, Nizeyi JB, Anderson S, Cooper JE, et al. (March 2000). "Field anesthesia of free-living mountain gorillas (Gorilla gorilla beringei) from the Virunga Volcano region, Central Africa". Journal of Zoo and Wildlife Medicine. 31 (1): 9–14. doi:10.1638/1042-7260(2000)031[0009:faoflm]2.0.co;2. PMID 10884117.
  5. ^ Cattet MR, Caulkett NA, Polischuk SC, Ramsay MA (September 1999). "Anesthesia of polar bears (Ursus maritimus) with zolazepam-tiletamine, medetomidine-ketamine, and medetomidine-zolazepam-tiletamine". Journal of Zoo and Wildlife Medicine. 30 (3): 354–60. PMID 10572857.