Cardiovascular effects of a proprietary l-methadone/fenpipramide combination (Polamivet) alone and in addition to acepromazine in healthy Beagle dogs.
OBJECTIVE
To determine the cardiovascular effects of a proprietary l-methadone/fenpipramide combination (Polamivet) alone and in addition to acepromazine in dogs.


METHODS
Prospective, randomized, experimental crossover study.


METHODS
Five adult healthy Beagle dogs (one male and four females, weighing 12.8-16.4 kg).


METHODS
Dogs were instrumented for haemodynamic measurements whilst anaesthetized with isoflurane. Three hours after recovery dogs received 0.025 mg kg(-1) acepromazine (AP) or saline (SP) IM followed by 0.5 mg kg(-1) L-methadone/ 0.025 mg kg(-1) fenpipramide IV after 30 minutes. Cardiac output using thermodilution, heart rate, mean arterial pressure (MAP), central venous pressure (CVP), mean pulmonary artery pressure (MPAP), pulmonary artery occlusion pressure (PAOP), haemoglobin concentration, arterial and mixed-venous blood gas analysis were measured and sedation evaluated at baseline (BL), 30 minutes after acepromazine or saline IM (A/S), 5 minutes after L-methadone/fenpipramide IV application (35), every 15 minutes for 1 hour (50, 65, 80, 95 minutes) and every hour until baseline cardiac output was regained. Standard cardiovascular parameters were calculated. Data were analyzed by repeated measures anova and paired t-tests with p < 0.05 considered significant.


RESULTS
Baseline measurements did not differ. Cardiac index decreased after acepromazine administration in treatment AP (p = 0.027), but was not significantly influenced after l-methadone/fenpipramide injection in either treatment. In both treatments heart rate did not change significantly over time. Stroke volume index increased after A/S in both treatments (p = 0.049). Systemic vascular resistance index, MAP, CVP, MPAP, and pulmonary vascular resistance index did not change significantly after either treatment and did not differ between treatments. Dogs were deeply sedated in both treatments with a longer duration in treatment AP.


CONCLUSIONS
In healthy dogs the dose of l-methadone/fenpipramide used in this study alone and in combination with acepromazine induced deep sedation without significant cardiovascular changes.
Small Animal Clinic, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany. julia.tuensmeyer@tiho-hannover.de
Julia
J
Tünsmeyer
Bernhard
B
Vaske
Britta
B
Bösing
Sabine B R
SB
Kästner
D000075:Acepromazine / Q000008:administration & dosage / Q000494:pharmacology*; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D018592:Cross-Over Studies; D004158:Diphenylacetic Acids / Q000008:administration & dosage / Q000494:pharmacology*; D004285:Dogs; D018492:Dopamine Antagonists / Q000008:administration & dosage / Q000494:pharmacology; D004338:Drug Combinations; D004359:Drug Therapy, Combination; D005260:Female; D006339:Heart Rate / Q000187:drug effects*; D006993:Hypnotics and Sedatives / Q000494:pharmacology; D008297:Male; D008691:Methadone / Q000008:administration & dosage / Q000494:pharmacology*; D013318:Stroke Volume / Q000187:drug effects; D014655:Vascular Resistance / Q000187:drug effects
D000701:Analgesics, Opioid; D004158:Diphenylacetic Acids; D018492:Dopamine Antagonists; D004338:Drug Combinations; D006993:Hypnotics and Sedatives; D000075:Acepromazine; C003148:fenpipramide; D008691:Methadone