Article · Wikipedia archive · Last revised Jul 23, 2026

Imepitoin

Imepitoin, sold under the brand name Pexion, is an anticonvulsant which is used in veterinary medicine in Europe to treat epilepsy in dogs. It was approved in the United States for veterinary use in December 2018. The drug also has anxiolytic effects. It was originally developed to treat epilepsy in humans, but clinical trials were terminated upon findings of unfavorable metabolic differences in smokers and non-smokers.

Last revised
Jul 23, 2026
Read time
≈ 1 min
Length
305 w
Citations
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Source
Wikipedia ↗
Imepitoin
Clinical data
Trade namesPexion
Other namesAWD 131-138; ELB-138
Routes of
administration		Oral
ATCvet code
Identifiers
  • 3-(4-Chlorophenyl)-5-morpholin-4-yl-4H-imidazol-2-one
CAS Number
PubChem CID
ChemSpider
UNII
ChEMBL
CompTox Dashboard (EPA)
ECHA InfoCard100.220.751
Chemical and physical data
FormulaC13H14ClN3O2
Molar mass279.72 g·mol−1
3D model (JSmol)
  • C1COCCN1C2=NC(=O)N(C2)C3=CC=C(C=C3)Cl
  • InChI=1S/C13H14ClN3O2/c14-10-1-3-11(4-2-10)17-9-12(15-13(17)18)16-5-7-19-8-6-16/h1-4H,5-9H2
  • Key:IQHYCZKIFIHTAI-UHFFFAOYSA-N

Imepitoin (INNTooltip International Nonproprietary Name), sold under the brand name Pexion, is an anticonvulsant which is used in veterinary medicine in Europe to treat epilepsy in dogs.1234 It was approved in the United States for veterinary use in December 2018.5 The drug also has anxiolytic effects.12 It was originally developed to treat epilepsy in humans, but clinical trials were terminated upon findings of unfavorable metabolic differences in smokers and non-smokers.12

Imepitoin acts as a low-affinity (4,350–5,140 nM; relative to Ki = 6.8 nM for diazepam and Ki = 1.7 nM for clonazepam) partial agonist of the benzodiazepine site of the GABAA receptor (up to 12–21% of the maximal potentiation of diazepam, a full agonist of this site).1 It is the first partial agonist to be approved for the treatment of epilepsy.1 The drug also dose-dependently blocks voltage-gated calcium channels.3 It is not a benzodiazepine; instead, it is an imidazolone, and bears some structural similarities to hydantoin anticonvulsants like ethotoin and phenytoin.1

See also

See also

References

References

  1. Rundfeldt C, Löscher W (2014). "The pharmacology of imepitoin: the first partial benzodiazepine receptor agonist developed for the treatment of epilepsy". CNS Drugs. 28 (1): 29–43. doi:10.1007/s40263-013-0129-z. PMID 24357084. S2CID 31627280.
  2. Sanders S (29 April 2015). "Antiseizure Medications". Seizures in Dogs and Cats. Wiley. pp. 209–. ISBN 978-1-118-68970-7.
  3. Thomas WB, Dewey CW (8 September 2015). "Seizures and Narcolepsy". In Dewey CW, da Costa RC (eds.). Practical Guide to Canine and Feline Neurology. Wiley. p. 259. ISBN 978-1-119-06204-2.
  4. "Imepitoin". drugs.com. Archived from the original on 2019-06-17. Retrieved 2017-09-17.
  5. "Original New Animal Drug Application". Animal Drugs at FDA. Retrieved 8 March 2026.