The Effect of a Combination of Medetomidine‐butorphanol and Medetomidine, Butorphanol, Atropine on Glomerular Filtration Rate in Dogs

Abstract

The effects of intramuscularly administered medetomidine and butorphanol (MB), and medetomidine, butorphanol, atropine (MBA) on glomerular filtration rate (GFR) were determined in six dogs as measured by 99m-Tc-labeled diethylenetriaminepentaacetic acid (99mTc-DTPA) nuclear scintigraphy. Direct systolic, diastolic, and mean arterial blood pressures and heart rate were measured at regular time intervals before, during, and after GFR calculations. The mean GFR measurement following MB was significantly greater (4.44 ml/min/kg) than following MBA (3.82 ml/min/kg) or saline treatment (3.41 ml/min/kg). There was no significant difference between the mean GFR measurements following MBA injection and following saline injection. Diastolic and mean arterial pressures following MBA injection were significantly higher than the values recorded after either MB or saline alone. Heart rate following MB administration was significantly lower than that recorded for dogs receiving MBA or saline alone. The results of this study indicate that the administration of medetomidine in combination with butorphanol significantly increases total GFR in healthy dogs, while the administration of the combination of medetomidine, butorphanol, and atropine does not.

Renal Effects of Medetomidine in Isoflurane-Anesthetized Dogs with Special Reference to Its Diuretic Action

“…The observed major effects of anesthesia on renal functions have been reported to be due to indirect circulatory and neuroendocrine responses [4,12]. Alpha 2 -adrenoceptor agonists have been shown to have many advantages desired in anesthetic, which include sedation, analgesia and muscle relaxation [14,15,26], however, previous studies have demonstrated the ability of these drugs to alter hemodynamic, initially they rise mean arterial blood pressure (MABP) due to their effects on postsynaptic α 2 -adrenoceptors with the resultant increase in systemic vascular resistance [27], this is followed by long-lasting decrease due to stimulation of central and peripheral presynaptic α 2 -adrenoceptors, therefore decrease sympathetic outflow and reduce cardiac output.…”

Effects of Tepoxalin and Medetomidine on Glomerular Filtration Rate in Dogs

“…Administration of medetomidine 50 µg/kg, IV decreases renal uptake of technetium 99m-labeled diethylenetriamine pentaacetic acid ( 99m Tc-DTPA) for 15 min after administration in dogs [12] and 10 µg/kg, IV of dexmedetomidine decreased renal blood flow by 30% in dogs anesthetized with chloralose and urethane or fentanyl and halothane [23]. In contrast, medetomidine (11 µg/kg, IV) administered with butorphanol (0.22 mg/kg, IV) increased GFR in dogs [15]. In human thoracotomy patients, administration of a dexmedetomidine infusion was shown to enhance renal function, including indices of glomerular filtration as well as urine flow rate [10].…”

Effect of Nephrotomy on Renal Function and Morphology in Normal Cats

“…[90][91][92] Some drug combinations commonly used in veterinary medicine have been shown to increase GFR, thought to be due to constriction of efferent arterioles resulting in increased glomerular hydrostatic pressure. 92 In cases of systemic hypotension resulting from sedative administration, GFR is usually sustained at normal levels by maintenance of renal blood flow. 90,91 Animals studied by Gahring et al 13 were anesthetized with thiamylal sodium and maintained with methoxyflurane and oxygen.…”