Advertisement

Sedative, analgesic, and cardiovascular effects of levomedetomidine alone and in combination with dexmedetomidine in dogs

Erja Kuusela DVM1, Outi Vainio DVM, PhD2, Anu Kaistinen DVM3, Sanna Kobylin DVM4, and Marja Raekallio DVM, PhD5
View More View Less
  • 1 Faculty of Veterinary Medicine, Department of Clinical Sciences, University of Helsinki, Hämeentie 57 FIN-00014, Finland.
  • | 2 Faculty of Veterinary Medicine, Department of Clinical Sciences, University of Helsinki, Hämeentie 57 FIN-00014, Finland.
  • | 3 Faculty of Veterinary Medicine, Department of Clinical Sciences, University of Helsinki, Hämeentie 57 FIN-00014, Finland.
  • | 4 Faculty of Veterinary Medicine, Department of Clinical Sciences, University of Helsinki, Hämeentie 57 FIN-00014, Finland.
  • | 5 Faculty of Veterinary Medicine, Department of Clinical Sciences, University of Helsinki, Hämeentie 57 FIN-00014, Finland.

Abstract

Objective—To determine whether a high dose of levomedetomidine had any pharmacologic activity or would antagonize the sedative and analgesic effects of dexmedetomidine in dogs.

Animals—6 healthy Beagles.

Procedure—Each dog received the following treatments on separate days: a low dose of levomedetomidine (10 µg/kg), IV, as a bolus, followed by continuous infusion at a dose of 25 µg/kg/h; a high dose of levomedetomidine (80 µg/kg), IV, as a bolus, followed by continuous infusion at a dose of 200 µg/kg/h; and a dose of isotonic saline (0.9% NaCl) solution, IV, as a bolus, followed by continuous infusion (control). For all 3 treatments, the infusion was continued for 120 minutes. After 60 minutes, a single dose of dexmedetomidine (10 µg/kg) was administered IV. Sedation and analgesia were scored subjectively, and heart rate, blood pressure, respiratory rate, arterial blood gas partial pressures, and rectal temperatures were monitored.

Results—Administration of levomedetomidine did not cause any behavioral changes. However, administration of the higher dose of levomedetomidine enhanced the bradycardia and reduced the sedative and analgesic effects associated with administration of dexmedetomidine.

Conclusion and Clinical Relevance—Results suggest that administration of dexmedetomidine alone may have some cardiovascular benefits over administration of medetomidine, which contains both dexmedetomidine and levomedetomidine. Further studies are needed to confirm the clinical importance of the effects of levomedetomidine in dogs. (Am J Vet Res 2001;62:616–621)

Abstract

Objective—To determine whether a high dose of levomedetomidine had any pharmacologic activity or would antagonize the sedative and analgesic effects of dexmedetomidine in dogs.

Animals—6 healthy Beagles.

Procedure—Each dog received the following treatments on separate days: a low dose of levomedetomidine (10 µg/kg), IV, as a bolus, followed by continuous infusion at a dose of 25 µg/kg/h; a high dose of levomedetomidine (80 µg/kg), IV, as a bolus, followed by continuous infusion at a dose of 200 µg/kg/h; and a dose of isotonic saline (0.9% NaCl) solution, IV, as a bolus, followed by continuous infusion (control). For all 3 treatments, the infusion was continued for 120 minutes. After 60 minutes, a single dose of dexmedetomidine (10 µg/kg) was administered IV. Sedation and analgesia were scored subjectively, and heart rate, blood pressure, respiratory rate, arterial blood gas partial pressures, and rectal temperatures were monitored.

Results—Administration of levomedetomidine did not cause any behavioral changes. However, administration of the higher dose of levomedetomidine enhanced the bradycardia and reduced the sedative and analgesic effects associated with administration of dexmedetomidine.

Conclusion and Clinical Relevance—Results suggest that administration of dexmedetomidine alone may have some cardiovascular benefits over administration of medetomidine, which contains both dexmedetomidine and levomedetomidine. Further studies are needed to confirm the clinical importance of the effects of levomedetomidine in dogs. (Am J Vet Res 2001;62:616–621)