Objective—To determine the effect of IV administration of perzinfotel on the minimum alveolar concentration (MAC) of isoflurane in dogs.
Animals—6 healthy sexually intact male Beagles.
Procedures—Dogs were instrumented with a telemetry device that permitted continuous monitoring of heart rate, arterial blood pressure, and body temperature. Dogs were anesthetized with propofol (4 to 6 mg/kg, IV) and isoflurane for 30 minutes before determination of MAC of isoflurane. Isoflurane MAC values were determined 4 times, separated by a minimum of 7 days, before and after IV administration of perzinfotel (0 [control], 5, 10, and 20 mg/kg). Bispectral index and percentage hemoglobin saturation with oxygen (SpO2) were monitored throughout anesthesia.
Results—Isoflurane MAC was 1.32 ± 0.14%. Intravenous administration of perzinfotel at 0, 5, 10, and 20 mg/kg decreased isoflurane MAC by 0%, 24%, 30%, and 47%, respectively. Perzinfotel significantly decreased isoflurane MAC values, compared with baseline and control values. The bispectral index typically increased with higher doses of perzinfotel and lower isoflurane concentrations, but not significantly. Heart rate, body temperature, and SpO2 did not change, but systolic, mean, and diastolic arterial blood pressures significantly increased with decreases in isoflurane MAC after administration of perzinfotel at 10 and 20 mg/kg, compared with 0 and 5 mg/kg.
Conclusions and Clinical Relevance—IV administration of perzinfotel decreased isoflurane MAC values. Improved hemodynamics were associated with decreases in isoflurane concentration.
Objective—To determine the effects of IV administration of perzinfotel and a perzinfotel-fentanyl combination on the minimum alveolar concentration (MAC) of isoflurane in dogs.
Animals—6 healthy sexually intact Beagles (3 males and 3 females).
Procedures—All dogs were instrumented with a telemetry device for continuous monitoring of heart rate, arterial blood pressure, and core body temperature (at a femoral artery). Dogs were anesthetized with propofol (6 mg/kg, IV) and isoflurane. Isoflurane MAC values were determined in 3 experiments in each dog, separated by at least 7 days, before (baseline) and after the following treatments: no treatment (anesthetic only), perzinfotel (20 mg/kg, IV), fentanyl (5 μg/kg bolus, IV, followed by a continuous IV infusion at 0.15 μg/kg/min), and a fentanyl-perzinfotel combination (20 mg of perzinfotel/kg, IV, plus the fentanyl infusion). Bispectral index and oxygen saturation as measured by pulse oximetry were also monitored throughout anesthesia.
Results—Without treatment, the mean ± SD isoflurane MAC for all 6 dogs was 1.41 ± 0.10%. Baseline MAC was 1.42 ± 0.08%. Intravenous administration of perzinfotel, fentanyl, and the perzinfotel-fentanyl combination significantly decreased the MAC by 39%, 35%, and 66%, respectively. Perzinfotel and perzinfotel-fentanyl administration yielded significant increases in the bispectral index. Mean, systolic, and diastolic arterial blood pressures significantly increased from baseline values when perzinfotel was administered. Systolic arterial blood pressure significantly increased from the baseline value when perzinfotel-fentanyl was administered. No adverse effects were detected.
Conclusions and Clinical Relevance—IV administration of perzinfotel, fentanyl, or a perzinfotel-fentanyl combination reduced isoflurane MAC in dogs and increased arterial blood pressure.
Objective—To investigate the ability of perzinfotel (an N-methyl-d-aspartate receptor antagonist) and a proprietary phospholipase A2 (PLA2) inhibitor to attenuate lameness in dogs with sodium urate (SU)–induced synovitis.
Animals—8 adult dogs.
Procedures—A blinded 4-way crossover study was performed. Dogs received perzinfotel (10 mg/kg), a proprietary PLA2 inhibitor (10 mg/kg), carprofen (4.4 mg/kg; positive control treatment), or no treatment (negative control treatment). On the fourth day after initiation of treatment, synovitis was induced via intra-articular injection of SU 1 hour before administration of the last treatment dose. Ground reaction forces were measured and clinical lameness evaluations were performed before (baseline [time 0]) and 2, 4, 6, 8, 12, and 25 hours after SU injection. There was a 21-day washout period between subsequent treatments. Data were analyzed via repeated-measures ANOVAs.
Results—Peak vertical force (PVF) and vertical impulse (VI) values for negative control and perzinfotel treatments were significantly lower at 2 and 4 hours, compared with baseline values. Values for PVF and VI for the PLA2 inhibitor and positive control treatments did not differ from baseline values at any time points. Between-treatment comparisons revealed significantly higher PVF and VI values for the positive control treatment than for the negative control and perzinfotel treatments at 2 and 4 hours. Values for VI were higher for PLA2 inhibitor treatment than for negative control treatment at 2 hours.
Conclusions and Clinical Relevance—Perzinfotel did not significantly alter SU–induced lameness. The proprietary PLA2 inhibitor attenuated lameness but not as completely as did carprofen.