Introduction

Name

• Dexmedetomidine hydrochloride.

Class of drug

• Alpha2 adrenergic agonist.

Description

Chemical name

• [+]4-[1-[2,3-dimethylphenyl]-ethyl]-1H-imidazole
• (S)-4(5)-[1-(2,3-Dimethylphenyl) ethyl]imidazole tartrate

Molecular formula

• C13H16N2.HCl

Molecular weight

• 236.7

Physical properties

• White or almost white powder that is freely soluble in water and has a pKa of 7.1. Partition coefficient in octanol: water at pH 7.4 is 2.89.
• Supplied as a clear, colorless solution for injection with methyl parahydroxybenzoate (E 218, 1.6 mg/ml) and propyl parahydroxybenzoate (E 216, 0.2 mg/ml) as excipients.

Storage requirements

• May be stored for 28 days at 25°C after withdrawal of the first dose.
• Do not freeze.

Uses

Administration

Pharmacokinetics

Precautions

Interactions

with other drugs

• Induction agents (eg propofol Propofol , thiopental Thiopental ):
  • Premedication with dexmedetomidine will significantly reduce the dosage of the induction agent (by 30% to 60%, depending on the agent).
  • Attention should be given during the administration of intravenous induction drugs to effect.
• Volatile anesthetics:
  • Requirements for maintenance anesthesia are reduced.
• Opioid analgesics Analgesia: opioid :
  • In dogs, concomitant use with butorphanol may lead to altered respiratory rate and character (see Adverse Effects), hypoxaemia, excitation, muscluloskeletal signs (see Adverse Effects) hypersalivation, gastrointestinal signs (see Adverse Effects), urination, skin erythema, sudden arousal or prolonged sedation.
  • Vasodilators (eg angiotensin-converting-enzyme inhibitors) and negative chronotropes (eg Beta-Blockers) may potentiate the effects of dexmedetomidine. Do not use in animals with cardiovascular disorders.
  • Central nervous system depressants, such as tricyclic antidepressants (eg clomipramine Clomipramine hydrochloride ), may potentiate the effects of dexmedetomidine. Dose adjustment should be made.

with diagnostic tests

• Alpha2-agonists increase blood glucose concentration.

Adverse Reactions

Further Reading

Publications

Refereed papers

• Recent references from PubMed and VetMedResource.
• Valtolina C, Robben J H, Uilenreef J et al (2009) Clinical evaluation of the efficacy and safety of a constant rate infusion of dexmedetomidine for postoperative pain management in dogs. Vet Anaesth Analg 36 (4), 369-383 PubMed.
• Granholm M, McKusick B C, Westerholm F C et al (2007) Evaluation of the clinical efficacy and safety of intramuscular and intravenous doses of dexmedetomidine and medetomidine in dogs and their reversal with atipamezole. Vet Rec 160 (26), 891-897 PubMed.
• Gómez-Villamandos R J, Palacios C, Benítez A et al (2006) Dexmedetomidine or medetomidine premedication before propofol-desflurane anaesthesia in dogs. J Vet Pharmacol Ther 29 (3), 157-163 PubMed.
• Granholm M, McKusick B C, Westerholm F C et al (2006) Evaluation of the clinical efficacy and safety of dexmedetomidine or medetomidine in cats and their reversal with atipamezole. Vet Anaesth Analg 33 (4), 214-223 PubMed.
• Leppänen M K, McKusick B C, Granholm M M et al (2006) Clinical efficacy and safety of dexmedetomidine and buprenorphine, butorphanol or diazepam for canine hip radiography. J Small Anim Pract 47 (11), 663-669 PubMed.
• Murrell J C, Hellebrekers L J (2005) Medetomidine and dexmedetomidine: a review of cardiovascular effects and antinociceptive properties in the dog. Vet Anaesth Analg 32 (3), 117-127 PubMed.
• Kuusela E, Raekallio M, Väisänen M et al (2001) Comparison of medetomidine and dexmedetomidine as premedicants in dogs undergoing propofol-isoflurane anesthesia. Am J Vet Res 62 (7), 1073-1080 PubMed.

Other sources of information

• Murrell J (2009) Dexmedetomidine (Dexdomitor®). UK Vet 14, 43-48.
• Association of Veterinary Anaesthetists (2009) Dexmedetomidine publications http://ava.eu.com/resources/uploads/images/pdf/Dexmedetomidine%20Publications.pdf Accessed March 4, 2009.
• Murrell J (2009) Dexmedetomidine in cardiac disease: whats the controversy?http://www.ava.eu.com/resources/uploads/images/pdf/partners,%20dexmedetomidine.PDF Accessed March 4, 2009.
• National Office of Animal Health (2009) Datasheet for Dexdomitorhttp://www.noahcompendium.co.uk/Pfizer_Limited/Dexdomitor_0_5_mg_ml_Solution_for_Injection/-46763.html Accessed March 4, 2009.
• EMEA (2008) Summary of Product Characteristics of Dexdomitor http://www.emea.europa.eu/vetdocs/PDFs/EPAR/dexdomitor/V-070-PI-en.pdf Accessed March 4, 2009.

Organisation(s)

• Association for Veterinary Pharmacology and Therapeutics E-mail:secretary@avcpt.org;http://www.avcpt.org/.
• Association of Veterinary Anaesthetists http://www.ava.eu.com/.