Cardiopulmonary effects of medetomidine-midazolam and medetomidine-midazolam- atipamezole in laboratory pigs.
The cardiopulmonary effects of medetomidine (40 micrograms/kg)-midazolam (0.2 mg/kg) and medetomidine (40 micrograms/kg)-midazolam (0.2 mg/kg)-atipamezole (160 micrograms/kg) were evaluated in laboratory pigs. The intramuscular administration of medetomidine-midazolam caused a pressor response, characterized by a rapid increase in arterial and pulmonary arterial pressure mediated mainly through systemic and pulmonary vasoconstriction. These pressures decreased after reaching a peak 5 to 10 min after the administration of sedatives, but maintained higher values than the base-line. However, all these changes caused by medetomidine-midazolam were within the physiological fluctuation. In addition, this combination did not induce bradycardia, subsequent hypotension or a significant decrease in cardiac output, which were generally observed with alpha 2-adrenoceptor agonists, and caused fewer changes in the respiratory system. The administration of atipamezole resulted in a marked transient decrease in vascular resistance, and caused a decrease in blood pressure and increases in cardiac output and heart rate. However, these changes were relatively small and sustained for a short time. Thus the combination of medetomidine-midazolam and atipamezole have minimal cardiopulmonary effects and might be used safely in laboratory pigs.
Nishimura
R
R
Department of Veterinary Surgery, Faculty of Agriculture, University of Tokyo, Japan.
Kim
H Y
HY
Matsunaga
S
S
Hayashi
K
K
Tamura
H
H
Sasaki
N
N
Takeuchi
A
A
D000316:Adrenergic alpha-Agonists / Q000494:pharmacology*; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology*; D000818:Animals; D000830:Animals, Laboratory; D001794:Blood Pressure / Q000187:drug effects; D002245:Carbon Dioxide / Q000097:blood; D002302:Cardiac Output / Q000187:drug effects; D004347:Drug Interactions; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D007093:Imidazoles / Q000494:pharmacology*; D008297:Male; D020926:Medetomidine; D008874:Midazolam / Q000494:pharmacology*; D009919:Orchiectomy; D010100:Oxygen / Q000097:blood; D010313:Partial Pressure; D011651:Pulmonary Artery / Q000187:drug effects / Q000502:physiology; D011652:Pulmonary Circulation / Q000187:drug effects*; D012119:Respiration / Q000187:drug effects*; D013552:Swine; D014655:Vascular Resistance / Q000187:drug effects
D000316:Adrenergic alpha-Agonists; D000317:Adrenergic alpha-Antagonists; D007093:Imidazoles; C050701:atipamezole; D002245:Carbon Dioxide; D020926:Medetomidine; D008874:Midazolam; D010100:Oxygen