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Suganthan H, Stefano DD, Buck LT. Alfaxalone is an effective anesthetic for the electrophysiological study of anoxia-tolerance mechanisms in western painted turtle pyramidal neurons. PLoS One 2024; 19:e0298065. [PMID: 38626211 PMCID: PMC11020846 DOI: 10.1371/journal.pone.0298065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 01/17/2024] [Indexed: 04/18/2024] Open
Abstract
Anoxia in the mammalian brain leads to hyper-excitability and cell death; however, this cascade of events does not occur in the anoxia-tolerant brain of the western painted turtle, Chrysemys picta belli. The painted turtle has become an important anoxia-tolerant model to study brain, heart, and liver function in the absence of oxygen, but being anoxia-tolerant likely means that decapitation alone is not a suitable method of euthanasia. Many anesthetics have long-term effects on ion channels and are not appropriate for same day experimentation. Using whole-cell electrophysiological techniques, we examine the effects of the anesthetic, Alfaxalone, on pyramidal cell action potential amplitude, threshold, rise and decay time, width, frequency, whole cell conductance, and evoked GABAA receptors currents to determine if any of these characteristics are altered with the use of Alfaxalone for animal sedation. We find that Alfaxalone has no long-term impact on action potential parameters or whole-cell conductance. When acutely applied to naïve tissue, Alfaxalone did lengthen GABAA receptor current decay rates by 1.5-fold. Following whole-animal sedation with Alfaxalone, evoked whole cell GABAA receptor current decay rates displayed an increasing trend with 1 and 2 hours after brain sheet preparation, but showed no significant change after a 3-hour washout period. Therefore, we conclude that Alfaxalone is a suitable anesthetic for same day use in electrophysiological studies in western painted turtle brain tissue.
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Affiliation(s)
- Haushe Suganthan
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Domenic Di Stefano
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Leslie T. Buck
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada
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Di Stefano D, Suganthan H, Buck L. Alfaxalone does not have long-term effects on goldfish pyramidal neuron action potential properties or GABA A receptor currents. FEBS Open Bio 2024; 14:555-573. [PMID: 38342633 PMCID: PMC10988724 DOI: 10.1002/2211-5463.13777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 11/30/2023] [Accepted: 01/31/2024] [Indexed: 02/13/2024] Open
Abstract
Anesthetics have varying physiological effects, but most notably alter ion channel kinetics. Alfaxalone is a rapid induction and washout neuroactive anesthetic, which potentiates γ-aminobutyric acid (GABA)-activated GABAA receptor (GABAA-R) currents. This study aims to identify any long-term effects of alfaxalone sedation on pyramidal neuron action potential and GABAA-R properties, to determine if its impact on neuronal function can be reversed in a sufficiently short timeframe to allow for same-day electrophysiological studies in goldfish brain. The goldfish (Carassius auratus) is an anoxia-tolerant vertebrate and is a useful model to study anoxia tolerance mechanisms. The results show that alfaxalone sedation did not significantly impact action potential properties. Additionally, the acute application of alfaxalone onto naive brain slices caused the potentiation of whole-cell GABAA-R current decay time and area under the curve. Following whole-animal sedation with alfaxalone, a 3-h wash of brain slices in alfaxalone-free saline, with saline exchanged every 30 min, was required to remove any potentiating impact of alfaxalone on GABAA-R whole-cell currents. These results demonstrate that alfaxalone is an effective anesthetic for same-day electrophysiological experiments with goldfish brain slices.
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Affiliation(s)
| | - Haushe Suganthan
- Department of Cell and Systems BiologyUniversity of TorontoCanada
| | - Leslie Buck
- Department of Cell and Systems BiologyUniversity of TorontoCanada
- Department of Ecology and Evolutionary BiologyUniversity of TorontoCanada
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Daskalaki M, Drummer C, Behr R, Heistermann M. The use of alfaxalone for short-term anesthesia can confound serum progesterone measurements in the common marmoset: a case report. Primate Biol 2022; 9:23-28. [PMID: 36034474 PMCID: PMC9399913 DOI: 10.5194/pb-9-23-2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 07/01/2022] [Indexed: 11/16/2022] Open
Abstract
Alfaxan® (alfaxalone) is a steroid general anesthetic widely used in veterinary medicine for induction and maintenance of anesthesia in several species. While the use of alfaxalone in veterinary practice has several benefits compared to the use of other anesthetic agents, the fact that it is derived from progesterone may confound the measurement of the latter in the blood of animals under alfaxalone treatment. In the present case study, we report the measurement of serum progesterone in an individual common marmoset (Callithrix jacchus) during five ovarian cycles in which luteolysis was
induced by PGF2α. Blood samples were usually taken from the awake
animal with the exception of the fifth cycle in which the sample was
collected under alfaxalone anesthesia in connection with a tooth extraction. In contrast to the previous four cycles in which luteolysis resulted in the expected marked decrease in progesterone concentrations, the – apparent – progesterone level in the cycle under alfaxalone treatment remained unexpectedly high. Cross-reactivity of the non-specific antibody used in the progesterone assay with alfaxalone most likely explains this finding.
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Affiliation(s)
- Maria Daskalaki
- Platform Degenerative Diseases, German Primate Center – Leibniz
Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, Germany
| | - Charis Drummer
- Platform Degenerative Diseases, German Primate Center – Leibniz
Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, Germany
| | - Rüdiger Behr
- Platform Degenerative Diseases, German Primate Center – Leibniz
Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, Germany
| | - Michael Heistermann
- Endocrinology Laboratory, German Primate Center – Leibniz Institute for Primate Research, Kellnerweg 4, 37077 Göttingen, Germany
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Timic Stamenic T, Manzella FM, Maksimovic S, Krishnan K, Covey DF, Jevtovic-Todorovic V, Todorovic SM. Further Evidence that Inhibition of Neuronal Voltage-Gated Calcium Channels Contributes to the Hypnotic Effect of Neurosteroid Analogue, 3β-OH. Front Pharmacol 2022; 13:850658. [PMID: 35677453 PMCID: PMC9169093 DOI: 10.3389/fphar.2022.850658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Accepted: 04/26/2022] [Indexed: 11/13/2022] Open
Abstract
We recently reported that a neurosteroid analogue with T-channel-blocking properties (3β,5β,17β)-3-hydroxyandrostane-17-carbonitrile (3β-OH), induced hypnosis in rat pups without triggering neuronal apoptosis. Furthermore, we found that the inhibition of the CaV3.1 isoform of T-channels contributes to the hypnotic properties of 3β-OH in adult mice. However, the specific mechanisms underlying the role of other subtypes of voltage-gated calcium channels in thalamocortical excitability and oscillations in vivo during 3β-OH-induced hypnosis are largely unknown. Here, we used patch-clamp recordings from acute brain slices, in vivo electroencephalogram (EEG) recordings, and mouse genetics with wild-type (WT) and CaV2.3 knock-out (KO) mice to further investigate the molecular mechanisms of neurosteroid-induced hypnosis. Our voltage-clamp recordings showed that 3β-OH inhibited recombinant CaV2.3 currents. In subsequent current-clamp recordings in thalamic slices ex vivo, we found that selective CaV2.3 channel blocker (SNX-482) inhibited stimulated tonic firing and increased the threshold for rebound burst firing in WT animals. Additionally, in thalamic slices we found that 3β-OH inhibited spike-firing more profoundly in WT than in mutant mice. Furthermore, 3β-OH reduced bursting frequencies in WT but not mutant animals. In ensuing in vivo experiments, we found that intra-peritoneal injections of 3β-OH were less effective in inducing LORR in the mutant mice than in the WT mice, with expected sex differences. Furthermore, the reduction in total α, β, and low γ EEG power was more profound in WT than in CaV2.3 KO females over time, while at 60 min after injections of 3β-OH, the increase in relative β power was higher in mutant females. In addition, 3β-OH depressed EEG power more strongly in the male WT than in the mutant mice and significantly increased the relative δ power oscillations in WT male mice in comparison to the mutant male animals. Our results demonstrate for the first time the importance of the CaV2.3 subtype of voltage-gated calcium channels in thalamocortical excitability and the oscillations that underlie neurosteroid-induced hypnosis.
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Affiliation(s)
- Tamara Timic Stamenic
- Department of Anesthesiology, University of Colorado, Anschutz Medical Campus, Aurora, United States
| | - Francesca M Manzella
- Department of Anesthesiology, University of Colorado, Anschutz Medical Campus, Aurora, United States
- Neuroscience Graduate Program, University of Colorado, Anschutz Medical Campus, Aurora, United States
| | - Stefan Maksimovic
- Department of Anesthesiology, University of Colorado, Anschutz Medical Campus, Aurora, United States
| | - Kathiresan Krishnan
- Department of Developmental Biology, Washington University School of Medicine, Saint Louis, MO, United States
| | - Douglas F Covey
- Department of Developmental Biology, Washington University School of Medicine, Saint Louis, MO, United States
- Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, Saint Louis, MO, United States
| | - Vesna Jevtovic-Todorovic
- Department of Anesthesiology, University of Colorado, Anschutz Medical Campus, Aurora, United States
| | - Slobodan M Todorovic
- Department of Anesthesiology, University of Colorado, Anschutz Medical Campus, Aurora, United States
- Neuroscience Graduate Program, University of Colorado, Anschutz Medical Campus, Aurora, United States
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Bennett K, Lewis K. Sedation and Anesthesia in Rodents. Vet Clin North Am Exot Anim Pract 2021; 25:211-255. [PMID: 34823692 DOI: 10.1016/j.cvex.2021.08.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Sedation and anesthesia in rodent species are complex due to their wide species variation, small size, and metabolism. This review article covers recent advances in sedation and anesthesia as well as an updated drug formulary for sedation protocols. Setup, equipment, monitoring, maintenance, and recovery are reviewed as well as species-specific anatomy.
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Affiliation(s)
- Katarina Bennett
- Avian & Exotics Service, Bluepearl Emergency and Specialty Hospital, 7414 S Tamiami Trl. Sarasota, FL 34231, USA.
| | - Kerrie Lewis
- Pebble Creek Animal Hospital, 19440 Bruce B Downs Boulevard, Tampa, FL 33647, USA
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Yang M, Jin L, Wu Z, Xie Y, Zhang P, Wang Q, Yan S, Chen B, Liang H, Naman CB, Zhang J, He S, Yan X, Zhao L, Cui W. PLGA-PEG Nanoparticles Facilitate In Vivo Anti-Alzheimer's Effects of Fucoxanthin, a Marine Carotenoid Derived from Edible Brown Algae. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:9764-9777. [PMID: 34404210 DOI: 10.1021/acs.jafc.1c00569] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The marine natural product fucoxanthin has been reported previously to produce anti-Alzheimer's disease (AD) neuroprotective effects in vitro and in vivo. Fucoxanthin was also demonstrated to be safe in preclinical and small population clinical studies, but the low bioavailability of fucoxanthin in the central nervous system (CNS) has limited its clinical applications. To overcome this, poly lactic-co-glycolic acid-block-polyethylene glycol loaded fucoxanthin (PLGA-PEG-Fuc) nanoparticles with diameter at around 200 nm and negative charge were synthesized and suggested to penetrate into the CNS. Loaded fucoxanthin could be liberated from PLGA-PEG nanoparticles by sustained released in the physiological environment. PLGA-PEG-Fuc nanoparticles were shown to significantly inhibit the formation of Aβ fibrils and oligomers. Moreover, these nanoparticles were taken up by both neurons and microglia, leading to the reduction of Aβ oligomers-induced neurotoxicity in vitro. Most importantly, intravenous injection of PLGA-PEG-Fuc nanoparticles prevented cognitive impairments in Aβ oligomers-induced AD mice with greater efficacy than free fucoxanthin, possibly via acting on Nrf2 and NF-κB signaling pathways. These results altogether suggest that PLGA-PEG nanoparticles can enhance the bioavailability of fucoxanthin and potentiate its efficacy for the treatment of AD, thus potentially enabling its future use for AD therapy.
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Affiliation(s)
- Mengxiang Yang
- Translational Medicine Center of Pain, Emotion and Cognition, Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo 315211, P. R. China
| | - Lingli Jin
- Faculty of Materials Science and Chemical Engineering, Ningbo University, Ningbo 315211, P. R. China
| | - Zhuoying Wu
- Translational Medicine Center of Pain, Emotion and Cognition, Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo 315211, P. R. China
| | - Yanfei Xie
- Translational Medicine Center of Pain, Emotion and Cognition, Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo 315211, P. R. China
| | - Panpan Zhang
- Translational Medicine Center of Pain, Emotion and Cognition, Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo 315211, P. R. China
| | - Qiyao Wang
- Translational Medicine Center of Pain, Emotion and Cognition, Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo 315211, P. R. China
| | - Sicheng Yan
- Translational Medicine Center of Pain, Emotion and Cognition, Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo 315211, P. R. China
| | - Bojun Chen
- Translational Medicine Center of Pain, Emotion and Cognition, Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo 315211, P. R. China
| | - Hongze Liang
- Faculty of Materials Science and Chemical Engineering, Ningbo University, Ningbo 315211, P. R. China
| | - C Benjamin Naman
- Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Research Center, Department of Marine Pharmacy, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315211, P. R. China
| | - Jinrong Zhang
- Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Research Center, Department of Marine Pharmacy, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315211, P. R. China
| | - Shan He
- Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Research Center, Department of Marine Pharmacy, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315211, P. R. China
| | - Xiaojun Yan
- Li Dak Sum Yip Yio Chin Kenneth Li Marine Biopharmaceutical Research Center, Department of Marine Pharmacy, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315211, P. R. China
| | - Lingling Zhao
- Faculty of Materials Science and Chemical Engineering, Ningbo University, Ningbo 315211, P. R. China
| | - Wei Cui
- Translational Medicine Center of Pain, Emotion and Cognition, Zhejiang Provincial Key Laboratory of Pathophysiology, School of Medicine, Ningbo University, Ningbo 315211, P. R. China
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Hawkins SJ, Doss GA, Mans C. Evaluation of subcutaneous administration of alfaxalone-midazolam and ketamine-midazolam as sedation protocols in African pygmy hedgehogs ( Atelerix albiventris). J Am Vet Med Assoc 2021; 257:820-825. [PMID: 33021455 DOI: 10.2460/javma.257.8.820] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To evaluate SC administration of 2 sedation protocols, ketamine-midazolam (KM) and alfaxalone-midazolam (AM), in African pygmy hedgehogs (Atelerix albiventris). ANIMALS 9 healthy adult hedgehogs (5 males, 4 females). PROCEDURES A randomized, blinded, complete crossover study was performed. Sedation was induced by SC administration of either ketamine (30 mg/kg [14 mg/lb]) with midazolam (1 mg/kg [0.45 mg/lb]) or alfaxalone (3 mg/kg [1.4 mg/lb]) with midazolam (1 mg/kg), including a 2-week washout period between treatments. Flumazenil (0.05 mg/kg [0.02 mg/lb], SC) was administered 45 minutes after administration of either protocol to reverse the effects of midazolam. Physiologic variables, reflexes, and behaviors were monitored. Food intake and body weight were measured before and after sedation. RESULTS Deep sedation characterized by complete loss of the righting reflex, decreased jaw tone, decreased pelvic limb withdrawal reflex, and preservation of the palpebral reflex was produced in 7 of 9 hedgehogs after KM administration and all 9 hedgehogs after AM administration. Mean ± SD time to loss of righting reflex was 6.4 ± 2.4 minutes after KM administration and 10 ± 4.0 minutes after AM administration. Following flumazenil administration, no significant difference was found in recovery time between sedation with KM (18.8 ± 12.7 minutes) and AM (14.4 ± 7.8 minutes). No significant differences were found in respiratory rate, oxygen saturation, or body temperature between protocols, whereas heart rate was higher for sedation with KM. Both sedation protocols resulted in a transient reduction in food intake. CONCLUSIONS AND CLINICAL RELEVANCE Subcutaneous administration of KM and AM provided deep sedation that might be useful to facilitate routine, noninvasive procedures in hedgehogs.
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EVALUATION OF TWO MEDETOMIDINE-AZAPERONE-ALFAXALONE COMBINATIONS IN CAPTIVE ROCKY MOUNTAIN ELK ( CERVUS ELAPHUS NELSONI). J Zoo Wildl Med 2021; 51:825-833. [PMID: 33480562 DOI: 10.1638/2020-0028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/11/2020] [Indexed: 11/21/2022] Open
Abstract
Alfaxalone has been successfully used intramuscularly (im) combined with medetomidine and azaperone for immobilization of small ungulates. An experimental 40 mg/ml alfaxalone solution (RD0387) was recently formulated for reduced injection volume. The objective of this study was to assess the efficacy and cardiopulmonary effects of high-concentration alfaxalone combined with medetomidine and azaperone for the intramuscular immobilization of captive Rocky Mountain elk (Cervus elaphus nelsoni). Seven adult female elk were used in a crossover design in which they were administered alfaxalone 1 mg/kg, medetomidine 0.05 mg/kg, and azaperone 0.1 mg/kg or alfaxalone 0.5 mg/kg, medetomidine 0.1 mg/kg, and azaperone 0.1 mg/kg im approximately 3 wk apart. Drugs were delivered to each elk in a chute by hand injection. Once recumbent, elk were placed in sternal recumbency for a period of 30 min, during which time level of sedation, response to minor procedures, heart rate, respiratory rate, rectal temperature, oxygen saturation, and direct arterial blood pressures were recorded every 5 min. Arterial blood gases were performed every 15 min. At 30 min, elk were administered atipamezole 0.25 or 0.5 mg/kg im and recovery quality and times were recorded. Statistical comparisons were made by t test, Wilcoxon signed rank test, and repeated measures analysis (significance level P < 0.05). Both drug combinations provided effective immobilization for 30 min, with induction and recovery time and quality similar to other medetomidine-based combinations used in elk. Cardiopulmonary effects included bradycardia, hypertension, and hypoxemia that resolved with oxygen supplementation. The average injection volume in the low-dose alfaxalone combination was approximately 5 ml. These combinations provided deep sedation and the ability to perform minor procedures in captive elk, with acceptable cardiopulmonary parameters as long as supplemental oxygen was provided.
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A Comparative Study of Intramuscular Alfaxalone- or Ketamine-Based Anesthetic Mixtures in Gray Squirrels Undergoing Gonadectomy: Clinical and Physiologic Findings. Animals (Basel) 2020; 10:ani10081402. [PMID: 32806590 PMCID: PMC7460254 DOI: 10.3390/ani10081402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 08/11/2020] [Accepted: 08/11/2020] [Indexed: 01/15/2023] Open
Abstract
The gray squirrel is one of the most common invasive species in Europe, whose presence is dangerous for the survival of the European red squirrel. To cope with this biological invasion and to safeguard biodiversity, the LIFE+U-SAVEREDS project aims to protect the red squirrel, by limiting the growth of the current population of gray squirrels and simultaneously promoting their eradication with surgical sterilization. This study compares two different anesthetic protocols, including dexmedetomidine (40 µg/kg) and midazolam (0.3 mg/kg) associated with ketamine (15 mg/kg; n = 25 squirrels) or alfaxalone (5 mg/kg; n = 22 squirrels). A blinded investigator evaluated the quality and onset of sedation, intraoperative anesthesia, and recovery, as well as the physiologic parameters for each animal. Alfaxalone provided a good quality of anesthesia with limited cardiovascular effects (p < 0.05) and good intraoperative myorelaxation. Ketamine induced complete relaxation in a shorter time (p < 0.05) and a rapid (p < 0.001) and excellent (p < 0.05) recovery. Despite the overall superiority of ketamine, alfaxalone appeared to be an adequate alternative anesthetic drug that can be administered without requiring intravascular access. It should be rapidly metabolized and excreted; however, it requires the combination of longer acting sedatives/myorelaxants to prevent a poor recovery quality.
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West SE, Lee JC, Johns TN, Nunamaker EA. Intraperitoneal Alfaxalone and Alfaxalone-Dexmedetomidine Anesthesia in Sprague-Dawley Rats ( Rattus norvegicus). JOURNAL OF THE AMERICAN ASSOCIATION FOR LABORATORY ANIMAL SCIENCE 2020; 59:531-538. [PMID: 32758333 DOI: 10.30802/aalas-jaalas-19-000161] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Due to their unpredictability and variable effects, injectable anesthetic regimens in laboratory rodent species warrant refinement. In our study we sought to evaluate alfaxalone, which has gained recent popularity in veterinary medicine, alone and in combination with dexmedetomidine to evaluate their anesthetic ability in Sprague-Dawley rats when administered intraperitoneally. Three doses of alfaxalone only and 4 dose combinations of alfaxalone-dexmedetomidine were tested in males and female rats. The time to induction, anesthetic duration, pulse rate, respiratory rate, temperature, and time to recovery were recorded by a blind observer. The level of anesthesia induced by the various anesthetic protocols was assessed by using pedal withdrawal reflex to a noxious stimulus and scored according to the response. Dependent on the treatment group, atipamezole or saline was administered intraperitoneally once animals reached 60 min of anesthesia. Regardless of the dose, alfaxalone alone achieved only a sedative level of anesthesia, whereas all alfaxalone-dexmedetomidine combinations led to a surgical level of anesthesia in all animals. Anesthesia regimens using alfaxalone alone and in combination with dexmedetomidine demonstrated sex-associated differences, with female rats maintaining longer durations of sedation or anesthesia than their male counterparts. Both male and female rats displayed decreases in physiologic parameters consistent with the effects of dexmedetomidine. Given the results described herein, we recommend 20 mg/kg alfaxalone for sedation and 30 mg/kg alfaxalone combined with 0.05 mg/kg dexmedetomidine for surgical anesthesia in female rats. Appropriate doses of alfaxalone only and alfaxalone-dexmedetomidine for male rats were not determined in this study and need further evaluation.
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Affiliation(s)
- Sylvia E West
- Animal Care Services, University of Florida, Gainesville, Florida;,
| | - Jonathan C Lee
- Animal Care Services, University of Florida, Gainesville, Florida
| | - Tinika N Johns
- Animal Care Services, University of Florida, Gainesville, Florida
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Ambar N, Eshar D, Shrader TC, Beaufrère H. Anesthetic Effects of Intramuscular Alfaxalone-Ketamine in Naked Mole Rats ( Heterocephalus glaber). JOURNAL OF THE AMERICAN ASSOCIATION FOR LABORATORY ANIMAL SCIENCE 2020; 59:539-545. [PMID: 32680579 DOI: 10.30802/aalas-jaalas-19-000170] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
In this study, adult intact male and female (n = 10) naked mole rats (Heterocephalus glaber) were anesthetized by using a combination of ketamine (20 mg/kg IM), and alfaxalone (4.0 mg/kg IM). Induction and recovery times were recorded. Vital parameters, including heart rate, respiratory rate, and reflexes, were monitored every 5 min during the anesthetic period. Anesthetic induction was smooth and rapid. Induction time was significantly longer in male rats (median, 325 s; range, 180 to 385 s) than in females (median, 145 s; range, 118 to 180 s). In addition, overall duration of loss of righting reflex was shorter in male mole rats (median, 50 min; range, 36 to 65 min) than females (median, 70 min; range, 60 to 85 min). Males largely had intact withdrawal reflexes, whereas females showed variable loss of both forelimb and hindlimb withdrawal reflexes. Neither recovery time (mean ± 1 SD, 16 ± 13 min) nor vital parameters differed between sexes. None of animals showed any anesthesia-related adverse responses. According to these findings, intramuscular AK is a safe and effective protocol that provides brief, light anesthesia in male naked mole rats and deeper anesthesia in females. We recommend adding analgesics when this AK protocol is used for pain-inducing or invasive procedures, and further studies evaluating higher doses and different combinations are indicated.
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Affiliation(s)
- Neta Ambar
- Department of Clinical Sciences, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas;,
| | - David Eshar
- Department of Clinical Sciences, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas
| | | | - Hugues Beaufrère
- Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, Canada
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Eshar D, Beaufrère H. Anesthetic Effects of Alfaxalone-Ketamine, Alfaxalone-Ketamine-Dexmedetomidine, and Alfaxalone-Butorphanol-Midazolam Administered Intramuscularly in Five‑striped Palm Squirrels (Funambulus pennantii). JOURNAL OF THE AMERICAN ASSOCIATION FOR LABORATORY ANIMAL SCIENCE : JAALAS 2020; 59. [PMID: 32471522 PMCID: PMC7338876 DOI: 10.30802/aalas-jaalas-19-000146] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 11/21/2019] [Accepted: 12/27/2019] [Indexed: 06/11/2023]
Abstract
Injectable anesthesia protocols for five-striped palm squirrels (Funambulus pennantii) are poorly described in the literature.In this study, male intact squirrels received intramuscular injections of either alfaxalone (6 mg/kg) and ketamine (40 mg/kg; AK group, n = 8); alfaxalone (6 mg/kg), ketamine (20 mg/kg), and dexmedetomidine (0.1 mg/kg; AKD group, n = 8); or alfaxalone (8 mg/kg), butorphanol (1 mg/kg), and midazolam (1 mg/kg; ABM group, n = 8). Atipamezole (0.15 mg/kg IM) and flumazenil (0.1 mg/kg IM) were administered 40 min after anesthesia induction (defined as loss of the righting reflex) with AKD and ABM, respectively. Heart rate, respiratory rate, rectal temperature, and reflexes were recorded every 5 min during anesthesia. Anesthetic induction was rapid in all groups (AK: median, 49 s; range, 33 to 60 s; AKD, 60 s; 54 to 70 s; and ABM, 15 s; 5 to 58 s). The anesthetic duration (from induction to full recovery) for the AK group was 62 ± 3 min (mean ± 1 SD). Therewas no statistically significant difference between the ABM and AKD groups regarding recovery time after partial antagonist administration and was 51 ± 5 and 48 ± 5 min, respectively. All AK animals showed twitching and abnormal vocalization during recovery. The righting reflex was absent in all squirrels for 20 min in the AK treatment group and throughout the 40-min anesthetic period in the AKD and ABM groups. The frontlimb withdrawal response was absent in all squirrels for the 40-min anesthetic period in the AKD and ABM groups, with variable responses for the AK treatment. All tested protocols in this study provided safe and effective immobilization in five-striped palm squirrels, but oxygen and thermal support wereindicated. Anesthetic depth must be determined before surgical procedures are performed in palm squirrels anesthetized by using these regimens.
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Affiliation(s)
- David Eshar
- Department of Clinical Sciences, College of Veterinary Medicine, Manhattan, Kansas; and
| | - Hugues Beaufrère
- Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Ontario, Canada
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13
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Whitehead MC, Hoppes SM, Musser JMB, Perkins JL, Lepiz ML. The Use of Alfaxalone in Quaker Parrots ( Myiopsitta monachus). J Avian Med Surg 2020; 33:340-348. [PMID: 31833302 DOI: 10.1647/2018-393] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Alfaxalone is a neurosteroid anesthetic that acts on gamma-aminobutyric acid alpha-receptors. The objective of this study was to evaluate the clinical safety and efficacy of alfaxalone (Alfaxan CD). Due to observed hyperexcitability in the subject animals when alfaxalone was the only drug used during the initial trials, premedication with midazolam was also evaluated during the final study. Ten adult Quaker parrots (Myiopsitta monachus) were assigned to 3 groups: 1) low-dose alfaxalone 10 mg/kg (LD), 2) high-dose alfaxalone 25 mg/kg (HD), and 3) alfaxalone 10 mg/ kg with midazolam 1 mg/kg premedication (AM), administered intramuscularly. Induction time, sedation quality, duration of action, and vital parameters, including heart rate, respiratory rate, and temperature, were recorded. All protocols achieved adequate sedation; however, muscle tremors and hyperexcitation were variable. The LD group had a significantly longer mean ± SD induction time (13.5 ± 4.5 minutes) as compared to the HD (6.0 ± 1.3 minutes, P = .002) and AM (6.5 ± 2.9 minutes, P = .006) groups, while recovery time was significantly longer in the HD group (86.2 ± 13.4 minutes) than the LD group (44.4 ± 10.8 minutes, P < .001). Midazolam premedication resulted in reduction of both muscle tremors and hyperexcitation associated with alfaxalone administration, but the recovery time was significantly longer (103.5 ± 15.1 minutes, P < .001) than for the LD group. Alfaxalone as a sole agent resulted in muscle tremors and hyperexcitation during induction, which was attenuated by premedication with midazolam. Further investigation is warranted to characterize the effects of alfaxalone and drugs used to premedicate Quaker parrots.
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Affiliation(s)
- Michelle C Whitehead
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843-4474, USA
| | - Sharman M Hoppes
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843-4474, USA
| | - Jeffrey M B Musser
- Department of Veterinary Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843-4467, USA
| | - Jennifer L Perkins
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843-4474, USA
| | - Mauricio L Lepiz
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843-4474, USA
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14
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Eshar D, Huckins GL, Shrader TC, Beaufrère H. Comparison of intramuscular administration of alfaxalone-ketamine-dexmedetomidine and alfaxalone-butorphanol-midazolam in naked mole-rats ( Heterocephalus glaber). Am J Vet Res 2020; 80:1089-1098. [PMID: 31763939 DOI: 10.2460/ajvr.80.12.1089] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To compare anesthetic effects of alfaxalone-ketamine-dexmedetomidine (AKD) and alfaxalone-butorphanol-midazolam (ABM) in naked mole-rats (Heterocephalus glaber). ANIMALS 20 naked mole-rats. PROCEDURES Naked mole-rats received AKD (alfaxalone, 2 mg/kg; ketamine, 20 mg/kg; and dexmedetomidine, 0.02 mg/kg; n = 10) or ABM (alfaxalone, 2 mg/kg; butorphanol, 2 mg/kg; and midazolam, 1 mg/kg; 9) IM; 1 animal was removed from the study. Atipamezole (I mg/kg) and flumazenil (0.1 mg/kg) were administered 40 minutes after anesthetic induction (defined as loss of the righting reflex) with AKD and ABM, respectively. Heart rate, respiratory rate, oxygen saturation, and reflexes were recorded every 5 minutes. RESULTS The ABM group had significantly longer median times for induction and recovery than the AKD group. Administration of ABM resulted in significantly lower respiratory rates than administration of AKD from time of anesthetic induction to 10 minutes after induction. Respiratory rate significantly decreased in the AKD group from I0 minutes after induction through the end of the anesthetic period but did not change over time in the ABM group. Males had higher respiratory rates in both groups. Loss of the righting reflex was still evident 40 minutes after induction in both groups. In the AKD group, all tested reflexes were absent from I0 to 40 minutes after induction; the ABM group had variable reflexes that recovered within individual animals over time. CONCLUSIONS AND CLINICAL RELEVANCE Both AKD and ABM provided effective immobilization in naked mole-rats, but AKD appeared to provide more consistent and deeper anesthesia, compared with administration of ABM.
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Heng K, Marx JO, Jampachairsi K, Huss MK, Pacharinsak C. Continuous Rate Infusion of Alfaxalone during Ketamine-Xylazine Anesthesia in Rats. JOURNAL OF THE AMERICAN ASSOCIATION FOR LABORATORY ANIMAL SCIENCE 2020; 59:170-175. [PMID: 32059754 DOI: 10.30802/aalas-jaalas-19-000122] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Alfaxalone is an injectable anesthetic agent that is used in veterinary medicine for general anesthesia. We evaluated the safety and efficacy of alfaxalone delivered through continuous rate infusion by comparing ketamine-xylazine-alfaxalone (KXA) anesthesia with ketamine-xylazine (KX) anesthesia in Sprague-Dawley rats. Anesthesia was induced in male and female rats by using subcutaneous KX. After induction, rats in the KXA group received alfaxalone (10 mg/kg/h IV) for 35 min, whereas rats in the KX group did not receive alfaxalone. At the end of the trial, alfaxalone was discontinued, and xylazine was reversed in all rats by using atipamezole. Throughout anesthesia, we assessed forepaw withdrawal reflex (FPWR), hindpaw withdrawal reflex (HPWR), response to surgical stimulation, heart rate, respiratory rate, SpO₂, body temperature, and time to standing. KXA produced a reliable surgical plane of anesthesia, as evidenced by the loss of both FPWR and HPWR and lack of response to surgical stimulation in all 16 rats, whereas only 6 of the 16 rats in the KX group lost HPWR. No rat in the KXA group regained a paw withdrawal reflex during alfaxalone administration, whereas 3 of the 12 rats (25%) in the KX group that reached a surgical plane of anesthesia exited that plane within the 35-min timeframe. Neither heart rate, respiratory rate, SpO₂, body temperature, nor time to standing differed between KXA and KX groups; and there were no sex-associated differences in anesthesia response. These results indicate that alfaxalone (10 mg/kg/h IV) delivered through continuous rate infusion, in combination with ketamine and xylazine, provides a safe, prolonged, and reliable surgical plane of anesthesia in rats.
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Affiliation(s)
- Kathleen Heng
- Department of Comparative Medicine, Stanford University, Stanford, California
| | - James O Marx
- University Laboratory Animal Resources, University of Pennsylvania, Philadelphia, Pennsylvania
| | | | - Monika K Huss
- Department of Comparative Medicine, Stanford University, Stanford, California;,
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16
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Marín P, Belda E, Laredo FG, Torres CA, Hernandis V, Escudero E. Pharmacokinetics and sedative effects of alfaxalone with or without dexmedetomidine in rabbits. Res Vet Sci 2019; 129:6-12. [PMID: 31901533 DOI: 10.1016/j.rvsc.2019.12.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 12/13/2019] [Accepted: 12/18/2019] [Indexed: 12/21/2022]
Abstract
This study aimed to investigate the specific pharmacokinetic profile and effects of alfaxalone after intravenous (IV) and intramuscular (IM) administration to rabbits and evaluate the potential interaction with dexmedetomidine. The study design was a blinded, randomized crossover with a washout period of 2 weeks. Five New Zealand white rabbits were used. Each animal received single IV and IM injections of alfaxalone at a single dose of 5 mg/kg, and single IV and IM injections of alfaxalone (5 mg/kg) combined with dexmedetomidine (100 μg/kg) administered intramuscularly. Blood samples were collected at predetermined times and analysed by high-performance liquid chromatography. The plasma concentration-time curves were analysed by non-compartmental analysis. Sedation/anaesthesia scores were evaluated by a modified numerical rating scale. At pre-determined time points heart and respiratory rates were measured. Times to sternal recumbency and standing position during the recovery were recorded. Concentrations of alfaxalone alone were very similar (slighty smaller) to concentrations when alfaxalone was combined with dexmedetomidine, after both routes of administration. Dexmedetomidine enhanced and increase the duration of the sedative effects of alfaxalone. In conclusion, alfaxalone administered in rabbits provides rapid and smooth onset of sedation. After IV and IM injections of alfaxalone combined with dexmedetomidine, a longer MRT and a deeper and extended sedation have been obtained compared to alfaxalone alone. Consequently, alfaxalone alone or in combination with dexmedetomidine could be useful to achieve respectively moderate to deep sedation in rabbits.
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Affiliation(s)
- Pedro Marín
- Department of Pharmacology, Faculty of Veterinary Medicine, University of Murcia, Murcia, Spain.
| | - Eliseo Belda
- Department of Animal Medicine and Surgery, Faculty of Veterinary Medicine, University of Murcia, Murcia, Spain
| | - Francisco G Laredo
- Department of Animal Medicine and Surgery, Faculty of Veterinary Medicine, University of Murcia, Murcia, Spain
| | - Crhystian A Torres
- Department of Animal Medicine and Surgery, Faculty of Veterinary Medicine, University of Murcia, Murcia, Spain
| | - Verónica Hernandis
- Department of Pharmacology, Faculty of Veterinary Medicine, University of Murcia, Murcia, Spain
| | - Elisa Escudero
- Department of Pharmacology, Faculty of Veterinary Medicine, University of Murcia, Murcia, Spain
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Kruse TN, Messenger KM, Bowman AS, Aarnes TK, Wittum TE, Flint M. Pharmacokinetics and pharmacodynamics of alfaxalone after a single intramuscular or intravascular injection in mallard ducks (Anas platyrhynchos). J Vet Pharmacol Ther 2019; 42:713-721. [PMID: 31435964 DOI: 10.1111/jvp.12804] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 06/26/2019] [Accepted: 07/16/2019] [Indexed: 11/27/2022]
Abstract
Pharmacokinetics and pharmacodynamics of alfaxalone was performed in mallard ducks (Anas platyrhynchos) after single bolus injections of 10 mg/kg administered intramuscularly (IM; n = 10) or intravenously (IV; n = 10), in a randomized cross-over design with a washout period between doses. Mean (±SD) Cmax following IM injection was 1.6 (±0.8) µg/ml with Tmax at 15.0 (±10.5) min. Area under the curve (AUC) was 84.66 and 104.58 min*mg/ml following IV and IM administration, respectively. Volume of distribution (VD ) after IV dose was 3.0 L/kg. The mean plasma clearance after 10 mg/kg IV was 139.5 (±67.9) ml min-1 kg-1 . Elimination half-lives (mean [±SD]) were 15.0 and 16.1 (±3.0) min following IV and IM administration, respectively. Mean bioavailability at 10 mg/kg IM was 108.6%. None of the ducks achieved a sufficient anesthetic depth for invasive procedures, such as surgery, to be performed. Heart and respiratory rates measured after administration remained stable, but many ducks were hyperexcitable during recovery. Based on sedation levels and duration, alfaxalone administered at dosages of 10 mg/kg IV or IM in mallard ducks does not induce clinically acceptable anesthesia.
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Affiliation(s)
- Tamara N Kruse
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio
| | - Kristen M Messenger
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
| | - Andrew S Bowman
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio
| | - Turi K Aarnes
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio
| | - Thomas E Wittum
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio
| | - Mark Flint
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio
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18
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Dehuisser V, Bosmans T, Devreese M, Gehring R, Croubels S, Duchateau L, Polis I. Alfaxalone total intravenous anaesthesia in dogs: pharmacokinetics, cardiovascular data and recovery characteristics. Vet Anaesth Analg 2019; 46:605-612. [PMID: 31395484 DOI: 10.1016/j.vaa.2019.04.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Revised: 03/14/2019] [Accepted: 04/24/2019] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To evaluate the cardiovascular effects, pharmacokinetic (PK) data and recovery characteristics of an alfaxalone constant rate infusion (CRI) of different duration in dogs at manufacturer's recommended dose rate. STUDY DESIGN Experimental, prospective, randomized, crossover study. ANIMALS Six intact female Beagles. METHODS Following an intravenous alfaxalone bolus (3 mg kg-1), anaesthesia was maintained using an alfaxalone CRI at 0.15 mg kg-1 minute-1 for 90 (short CRI) or 180 minutes (long CRI). Venous blood samples were collected to determine the PK profile. Cardiovascular variables and recovery characteristics were evaluated. Recovery was scored on a scale ranging from 0, excellent to 4, bad. A mixed-model statistical approach was used to compare the cardiovascular parameters (global α = 0.05). An analysis of variance was performed to compare PK parameters and recovery times between treatments. RESULTS No significant difference was noted between protocols for any PK parameter. Volume of distribution at steady state (935.74 ± 170.25 versus 1119.15 ± 190.65 mL kg-1), elimination half-life (12 ± 2 versus 13 ± 3 minutes), clearance from the central compartment (26.02 ± 4.41 versus 27.74 ± 5.65 mL kg-1 minute-1) and intercompartmental clearance (8.47 ± 4.06 versus 12.58 ± 7.03 mL kg-1 minute-1) were comparable for short CRI and long CRI. Cardiovascular variables remained within physiological limits. Mechanical ventilation was necessary (short CRI: n = 1, long CRI: n = 4). The manufacturer's recommended dose rate resulted in a light plane of anaesthesia. No significant differences in recovery times and scores were observed between treatments. The quality of recovery was scored as very poor with both protocols. CONCLUSIONS AND CLINICAL RELEVANCE PK data were similar between long and short infusions of alfaxalone at the manufacturer's recommended dose, with acceptable cardiovascular conditions. Nevertheless, both protocols resulted in a superficial plane of general anaesthesia with poor recovery characteristics.
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Affiliation(s)
- Virginie Dehuisser
- Department of Small Animals, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
| | - Tim Bosmans
- Department of Small Animals, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Mathias Devreese
- Department of Pharmacology, Toxicology and Biochemistry, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium; Institute of Computational Comparative Medicine, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA
| | - Ronette Gehring
- Institute of Computational Comparative Medicine, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA
| | - Siska Croubels
- Department of Pharmacology, Toxicology and Biochemistry, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Luc Duchateau
- Department of Comparative Physiology and Biometry, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Ingeborgh Polis
- Department of Small Animals, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
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19
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Tsukamoto Y, Yamada N, Miyoshi K, Yamashita K, Ohsugi T. Anesthetic effect of a mixture of alfaxalone, medetomidine, and butorphanol for inducing surgical anesthesia in ICR, BALB/c, and C57BL/6 mouse strains. J Vet Med Sci 2019; 81:937-945. [PMID: 31080189 PMCID: PMC6612492 DOI: 10.1292/jvms.18-0712] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The anesthetic effects of alfaxalone combined with medetomidine and butorphanol were
investigated for ICR, BALB/c, and C57BL/6 mice. Mice were administered a combination of
0.5 or 0.75 mg/kg medetomidine and 5 mg/kg butorphanol with 30 or 40 mg/kg alfaxalone
(0.5MBA30, 0.75MBA30 and 0.75MBA40, respectively). The drug combinations were administered
subcutaneously and were compared with a widely used combination of 0.3 mg/kg medetomidine,
4 mg/kg midazolam, and 5 mg/kg butorphanol (MMB). All three MBA combinations achieved
surgical anesthesia, although the recovery time was longer with 0.75MBA30 and 0.75MBA40
compared with 0.5MBA30. Furthermore, several mice exhibited a considerable jumping
reaction immediately after injection with 0.75MBA30 and 0.75MBA40. Therefore, 0.5MBA30 may
be suitable for inducing surgical anesthesia in the mouse strains tested. The anesthetic
scores for 0.5MBA30 were improved compared with those of MMB in all three mouse strains;
however, the body temperature drop in C57BL/6 mice was greater with 0.5MBA30. Our results
show that the alfaxalone combination, 0.5MBA30, should allow surgical operations that are
more stable in more strains of mice than MMB, although the combination may cause
hypothermia, especially in C57BL/6 mice.
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Affiliation(s)
- Yoriko Tsukamoto
- Department of Laboratory Animal Science, School of Veterinary Medicine, Rakuno-Gakuen University, 582 Bunkyodai-Midorimachi, Ebetsu, Hokkaido 069-8501, Japan
| | - Norihide Yamada
- Department of Laboratory Animal Science, School of Veterinary Medicine, Rakuno-Gakuen University, 582 Bunkyodai-Midorimachi, Ebetsu, Hokkaido 069-8501, Japan
| | - Kenjiro Miyoshi
- Department of Small Animal Clinical Sciences, School of Veterinary Medicine, Rakuno-Gakuen University, 582 Bunkyodai-Midorimachi, Ebetsu, Hokkaido 069-8501, Japan
| | - Kazuto Yamashita
- Department of Small Animal Clinical Sciences, School of Veterinary Medicine, Rakuno-Gakuen University, 582 Bunkyodai-Midorimachi, Ebetsu, Hokkaido 069-8501, Japan
| | - Takeo Ohsugi
- Department of Laboratory Animal Science, School of Veterinary Medicine, Rakuno-Gakuen University, 582 Bunkyodai-Midorimachi, Ebetsu, Hokkaido 069-8501, Japan
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20
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Lau C, Thakre PP, Bellingham MC. Alfaxalone Causes Reduction of Glycinergic IPSCs, but Not Glutamatergic EPSCs, and Activates a Depolarizing Current in Rat Hypoglossal Motor Neurons. Front Cell Neurosci 2019; 13:100. [PMID: 30967762 PMCID: PMC6440435 DOI: 10.3389/fncel.2019.00100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2018] [Accepted: 02/27/2019] [Indexed: 11/20/2022] Open
Abstract
We investigated effects of the neuroactive steroid anesthetic alfaxalone on intrinsic excitability, and on inhibitory and excitatory synaptic transmission to hypoglossal motor neurons (HMNs). Whole cell recordings were made from HMNs in brainstem slices from 7 to 14-day-old Wistar rats. Spontaneous, miniature, and evoked inhibitory post-synaptic currents (IPSCs), and spontaneous and evoked excitatory PSCs (EPSCs) were recorded at –60 mV. Alfaxalone did not alter spontaneous glycinergic IPSC peak amplitude, rise-time or half-width up to 10 μM, but reduced IPSC frequency from 3 μM. Evoked IPSC amplitude was reduced from 30 nM. Evoked IPSC rise-time was prolonged and evoked IPSC decay time was increased only by 10 μM alfaxalone. Alfaxalone also decreased evoked IPSC paired pulse ratio (PPR). Spontaneous glutamatergic EPSC amplitude and frequency were not altered by alfaxalone, and evoked EPSC amplitude and PPR was also unchanged. Alfaxalone did not alter HMN repetitive firing or action potential amplitude. Baseline holding current at −60 mV with a CsCl-based pipette solution was increased in an inward direction; this effect was not seen when tetrodotoxin (TTX) was present. These results suggest that alfaxalone modulates glycine receptors (GlyRs), causing a delayed and prolonged channel opening, as well as causing presynaptic reduction of glycine release, and activates a membrane current, which remains to be identified. Alfaxalone selectively reduces glycinergic inhibitory transmission to rat HMNs via a combination of pre- and post-synaptic mechanisms. The net effect of these responses to alfaxalone is to increase HMN excitability and may therefore underlie neuro-motor excitation during neurosteroid anesthesia.
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Affiliation(s)
- Cora Lau
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Prajwal P Thakre
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Mark C Bellingham
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
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Bradley MP, Doerning CM, Nowland MH, Lester PA. Intramuscular Administration of Alfaxalone Alone and in Combination for Sedation and Anesthesia of Rabbits ( Oryctolagus cuniculus). JOURNAL OF THE AMERICAN ASSOCIATION FOR LABORATORY ANIMAL SCIENCE 2019; 58:216-222. [PMID: 30819274 DOI: 10.30802/aalas-jaalas-18-000078] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
This study compared alfaxalone, alone and in combination with other medications, for sedative and anesthetic properties after intramuscular administration in New Zealand white rabbits. In the main portion of the study, 6 female rabbits were assigned to 5 treatment regimens in a blinded crossover design. Alfaxalone (6 mg/kg IM) was administered alone and in combination with each of the following: 0.3 mg/kg butorphanol; 1 mg/kg midazolam; 0.2 mg/kg dexmedetomidine; and both 0.3 mg/kg butorphanol and 0.2 mg/kg dexmedetomidine. An additional 6 rabbits received 0.2 mg/kg dexmedetomidine for comparison. The median time to onset of recumbency ranged from 2.0 to 5.5 min, with times significantly shorter for animals that received alfaxalone with either midazolam or dexmedetomidine than for those given dexmedetomidine only. Duration of sedation (mean ± 1 SD) was: alfaxalone only, 40 ± 7.3 min; alfaxalone with butorphanol, 47.8 ± 9.9 min; alfaxalone with midazolam, 65.2 ± 6.5 min; alfaxalone with dexmedetomidine, 157.5 ± 22.4 min; alfaxalone with butorphanol and dexmedetomidine, 157.7 ± 22.3 min, and dexmedetomidine only, 93.7 ± 11.9 min. Response to noxious stimuli was absent in 2 of the rabbits given dexmedetomidine only, 4 of those given alfaxalone with dexmedetomidine, and all 6 of the animals dosed with alfaxalone, butorphanol, and dexmedetomidine; this last group displayed the longest absence of a toe-pinch response (57 ± 3 min).
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Affiliation(s)
- Michael P Bradley
- Unit for Laboratory Animal Medicine; University of Michigan, Ann Arbor, Michigan, USA.
| | - Carolyn M Doerning
- Unit for Laboratory Animal Medicine; University of Michigan, Ann Arbor, Michigan, USA
| | - Megan H Nowland
- Unit for Laboratory Animal Medicine; University of Michigan, Ann Arbor, Michigan, USA
| | - Patrick A Lester
- Unit for Laboratory Animal Medicine; University of Michigan, Ann Arbor, Michigan, USA
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Erickson RL, Blevins CE, Souza Dyer CD, Marx JO. Alfaxalone-Xylazine Anesthesia in Laboratory Mice ( Mus musculus). JOURNAL OF THE AMERICAN ASSOCIATION FOR LABORATORY ANIMAL SCIENCE 2018; 58:30-39. [PMID: 30572981 DOI: 10.30802/aalas-jaalas-18-000010] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Since its recent reformulation, alfaxalone has gained popularity as an injectable veterinary anesthetic, including promising studies demonstrating the use of alfaxalone-xylazine for anesthesia in mice. Here we sought to expand these studies by testing additional dose ranges, elaborating on physiologic monitoring, testing sex- and strain-associated differences, and evaluating efficacy during actual surgical conditions. C57BL/6J mice showed significant sex-associated differences in anesthetic sensitivity, with males requiring higher doses of alfaxalone (80-120 mg/kg IP alfaxalone with 10 mg/kg IP xylazine) than females (40-80 mg/kg IP alfaxalone with 10 mg/kg IP xylazine) to achieve a surgical plane of anesthesia. In addition, female outbred CD1 mice were less sensitive to alfaxalone than female inbred C57BL/6J mice. When used during actual surgery, alfaxalone-xylazine administered intraperitoneally provided adequate anesthesia for a model of orthopedic surgery, whereas the same anesthetic regimen during laparotomy resulted in unacceptably high mortality; survival during laparotomy increased when drugs were administered subcutaneously. These results indicate that alfaxalone-xylazine may be a viable option for injectable surgical anesthesia in mice, although strain- and sex-associated differences and alternative routes of administration should be considered when optimizing the anesthetic regimen for specific experimental conditions.
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Affiliation(s)
- Rebecca L Erickson
- Center for Comparative Medicine, Northwestern University, Chicago, Illinois
| | | | - Cecilia De Souza Dyer
- Gene Therapy Program, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - James O Marx
- University Laboratory Animal Resources, University of Pennsylvania, Philadelphia, Pennsylvania, Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania;,
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23
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Whitehead MC, Vanetten CL, Jacob ME, Harrison TM. Microbial integrity of preservative-free alfaxalone in a multiple-use system for two storage conditions and three handling techniques. Am J Vet Res 2018; 79:704-710. [PMID: 29943636 DOI: 10.2460/ajvr.79.7.704] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To evaluate the microbial integrity of preservative-free cyclodextrin-based alfaxalone in a multiple-use system. SAMPLE 22 vials of preservative-free alfaxalone. PROCEDURES 2 storage conditions (room temperature, 22°C; refrigerated temperature, 4°C) and 3 handling techniques (closed system transfer device, nonclosed dispensing pin, and manufacturer-supplied vial stopper) comprised 6 treatment groups (3 replicates/group). An aliquot (0.5 mL) was withdrawn from each vial daily for 14 days. Samples were immediately inoculated into tryptic soy broth and incubated at 36°C for 24 hours; samples were subcultured onto 5% Columbia sheep blood agar and incubated for 48 hours. Isolated colonies were evaluated for identification. RESULTS There was no evidence of microbial contamination of vials stored for 7 days in refrigeration and handled with a protected port (closed system transfer device or nonclosed dispensing pin). CONCLUSIONS AND CLINICAL RELEVANCE The US FDA prohibits the use of alfaxalone beyond 6 hours after the vial stopper is broached (punctured), as mandated for a preservative-free injectable medication. Findings for the study reported here supported the use of alfaxalone for 7 days when refrigerated and handled with a single puncture of the stopper by use of a protected port (closed system transfer device or nonclosed dispensing pin). This would appear to be a practical alternative for an injectable anesthetic. It would minimize drug waste and the subsequent environmental impact for disposal of unused drug and allow standardization of storage and handling protocols for alfaxalone use in veterinary practices across the United States.
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Doerning CM, Bradley MP, Lester PA, Nowland MH. Effects of subcutaneous alfaxalone alone and in combination with dexmedetomidine and buprenorphine in guinea pigs (Cavia porcellus). Vet Anaesth Analg 2018; 45:658-666. [PMID: 30064914 DOI: 10.1016/j.vaa.2018.06.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 06/08/2018] [Accepted: 06/16/2018] [Indexed: 01/15/2023]
Abstract
OBJECTIVE To characterize alfaxalone administered subcutaneously (SC) in guinea pigs, both alone and in combination with dexmedetomidine and buprenorphine. STUDY DESIGN Prospective, blinded, crossover study. ANIMALS A total of 15 healthy female guinea pigs weighing 400-600 g. METHODS Alfaxalone (10, 20 and 40 mg kg-1) was administered SC to three guinea pigs as a pilot dose-finding study. Alfaxalone (20 mg kg-1; A20) was selected for comparison against combination protocols of alfaxalone (15 and 20 mg kg-1) with dexmedetomidine (0.25 mg kg-1) and buprenorphine (0.05 mg kg-1; A15DB, A20DB). Each protocol was randomly administered to 12 guinea pigs separated by ≥7 days. Time and quality of induction and recovery, heart rate, respiratory rate, peripheral hemoglobin oxygen saturation, rectal temperature, pedal withdrawal reflex and adverse effects were recorded. RESULTS The median time to induction for A20, A15DB and A20DB was 6.8-8.0 minutes with no significant difference between treatments. Mean duration of recumbency for A20 was 73.6 ± 19.6 minutes. Recumbency duration for A15DB and A20DB extended to 90 minutes, at which time dexmedetomidine was antagonized using atipamezole (0.025 mg kg-1 SC). Physiological variables were within normal limits with the exception of one animal that died 45 minutes following treatment with A20DB. Pedal withdrawal reflex remained intact with all treatments. Minor side effects such as twitching or bruxism occurred sporadically with treatment A20 but not with A15DB and A20DB. CONCLUSIONS AND CLINICAL RELEVANCE SC alfaxalone produced uncomplicated sedation that may be recommended for nonpainful procedures that do not require complete immobility. The addition of dexmedetomidine and buprenorphine increased the duration of sedation and immobility, but did not result in general anesthesia. This combination sedation protocol may be useful for nonpainful procedures requiring extended immobility.
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Affiliation(s)
- Carolyn M Doerning
- Unit for Laboratory Animal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Michael P Bradley
- Unit for Laboratory Animal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Patrick A Lester
- Unit for Laboratory Animal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Megan H Nowland
- Unit for Laboratory Animal Medicine, University of Michigan, Ann Arbor, MI, USA.
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Rodrigo-Mocholí D, Escudero E, Belda E, Laredo FG, Hernandis V, Marín P. Pharmacokinetics and effects of alfaxalone after intravenous and intramuscular administration to cats. N Z Vet J 2018; 66:172-177. [DOI: 10.1080/00480169.2018.1455541] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- D Rodrigo-Mocholí
- Faculty of Veterinary Medicine, Department of Veterinary Anaesthesia and Analgesia, University of Sydney, Camperdown, New South Wales, Australia
| | - E Escudero
- Faculty of Veterinary Medicine, Department of Pharmacology, University of Murcia, 30071 Espinardo, Murcia, Spain
| | - E Belda
- Faculty of Veterinary Medicine, Department of Animal Medicine and Surgery, University of Murcia, 30071 Espinardo, Murcia, Spain
| | - FG Laredo
- Faculty of Veterinary Medicine, Department of Animal Medicine and Surgery, University of Murcia, 30071 Espinardo, Murcia, Spain
| | - V Hernandis
- Faculty of Veterinary Medicine, Department of Pharmacology, University of Murcia, 30071 Espinardo, Murcia, Spain
| | - P Marín
- Faculty of Veterinary Medicine, Department of Pharmacology, University of Murcia, 30071 Espinardo, Murcia, Spain
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Arenillas M, Gomez de Segura IA. Anaesthetic effects of alfaxalone administered intraperitoneally alone or combined with dexmedetomidine and fentanyl in the rat. Lab Anim 2018; 52:588-598. [PMID: 29580166 DOI: 10.1177/0023677218764214] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Alfaxalone is a neuroactive steroid used as a general anaesthetic in several species including dogs, cats, rabbits and ferrets. It has a wide margin of safety and a similar anaesthetic profile to propofol. To increase its aqueous solubility, a new formulation with cyclodextrins has been marketed recently. The objective of this study was to evaluate the anaesthetic effect of several doses of alfaxalone alone, considering differences between sexes, and alfaxalone combined with dexmedetomidine and fentanyl in the rat administered by the intraperitoneal route. A total of 40 Sprague Dawley rats, involved in three studies, were used. Firstly, 25, 35 and 45 mg kg-1 of alfaxalone alone were tested. In a second study, alfaxalone (25 mg kg-1, females; 75 mg kg-1, males) was combined with dexmedetomidine (0.05 mg kg-1). Finally, alfaxalone (20 mg kg-1, females; 60 mg kg-1, males) was combined with dexmedetomidine (0.05 mg kg-1) and fentanyl (0.1 mg kg-1). Times of onset and duration of anaesthesia, and analgesia, deemed as losing of withdrawal pedal reflex, were recorded. Alfaxalone alone produced a 2 - to 3-fold longer time of anaesthesia in females, although surgical anaesthesia was not achieved in either sex. The addition of dexmedetomidine and fentanyl to alfaxalone produced a similar time of analgesia as well as increased time of anaesthesia in both sexes. In conclusion, alfaxalone produces light anaesthesia in rats, and males required a higher dose. The combination with other sedatives or analgesics, such as dexmedetomidine or fentanyl, allows a more prolonged anaesthesia with analgesic effects, potentially suitable for invasive procedures.
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Affiliation(s)
- Mario Arenillas
- Department of Animal Medicine and Surgery, Complutense University of Madrid, Spain
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Bakker J, Roubos S, Remarque EJ, Arndt SS, Kronen PW, Langermans JA. Effects of buprenorphine, butorphanol or tramadol premedication on anaesthetic induction with alfaxalone in common marmosets (Callithrix jacchus). Vet Anaesth Analg 2018; 45:309-319. [PMID: 29628389 DOI: 10.1016/j.vaa.2017.06.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 03/27/2017] [Accepted: 06/27/2017] [Indexed: 12/26/2022]
Abstract
OBJECTIVE To investigate the clinical and physiological effects of intravenous (IV) alfaxalone alone or in combination with buprenorphine, butorphanol or tramadol premedication in marmosets. STUDY DESIGN Prospective, randomized, blinded, crossover design. ANIMALS Nine healthy marmosets (391 ± 48 g, 3.7 ± 2.2 years old). METHODS Meloxicam 0.20 mg kg-1 subcutaneously, atropine 0.05 mg kg-1 intramuscularly (IM) and either buprenorphine 20 μg kg-1 IM (BUP-A), butorphanol 0.2 mg kg-1 IM (BUT-A), tramadol 1.5 mg kg-1 IM (TRA-A) or no additional drug (control) were administered to all marmosets as premedication. After 1 hour, anaesthesia was induced with 16 mg kg-1 alfaxalone IV. All animals received all protocols. The order of protocol allocation was randomized with a minimum 28 day wash-out period. During anaesthesia, respiratory and pulse rates, rectal temperature, haemoglobin oxygen saturation, arterial blood pressure, palpebral and pedal withdrawal reflexes and degree of muscle relaxation were assessed and recorded every 5 minutes. Quality of induction and recovery were assessed. Duration of induction, immobilization and recovery were recorded. Blood samples were analysed for aspartate aminotransferase, creatine kinase and lactate dehydrogenase concentrations. The protocols were compared using paired t tests, Wilcoxon's signed-rank test with Bonferroni's corrections and linear mixed effect models where appropriate. RESULTS Out of nine animals, apnoea was noted in eight animals administered protocol BUP-A and two animals administered protocol BUT-A. With TRA-A and control protocols, apnoea was not observed. No other significant differences in any of the parameters were found; however, low arterial blood pressures and hypoxia occurred in TRA-A. CONCLUSIONS AND CLINICAL RELEVANCE Our study employing different premedications suggests that the previously published dose of 16 mg kg-1 alfaxalone is too high when used with premedication because we found a high incidence of complications including apnoea (BUP-A), hypotension and hypoxaemia (TRA-A). Appropriate monitoring and countermeasures are recommended.
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Affiliation(s)
- Jaco Bakker
- Animal Science Department, Biomedical Primate Research Centre, Rijswijk, The Netherlands.
| | - Sandra Roubos
- Department of Animals in Science & Society, Division of Animal Welfare & Laboratory Animal Science, Faculty of Veterinary Medicine Utrecht University, Utrecht, The Netherlands
| | - Edmond J Remarque
- Department of Parasitology, Biomedical Primate Research Centre, Rijswijk, The Netherlands
| | - Saskia S Arndt
- Department of Animals in Science & Society, Division of Animal Welfare & Laboratory Animal Science, Faculty of Veterinary Medicine Utrecht University, Utrecht, The Netherlands
| | - Peter W Kronen
- Veterinary Anaesthesia Services - International, Winterthur, Switzerland
| | - Jan Am Langermans
- Animal Science Department, Biomedical Primate Research Centre, Rijswijk, The Netherlands
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El-Hawari SF, Sakata H, Oyama N, Tamura J, Higuchi C, Endo Y, Miyoshi K, Sano T, Suzuki K, Yamashita K. Anesthetic and cardiorespiratory effects of single-bolus intravenous alfaxalone with or without intramuscular xylazine-premedication in calves. J Vet Med Sci 2017; 80:361-367. [PMID: 29269688 PMCID: PMC5836778 DOI: 10.1292/jvms.17-0512] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The anesthetic and cardiorespiratory effects of xylazine-alfaxalone combination were
evaluated in calves. Six calves (age: 6–9 months old; weight: 114–310 kg) were
anesthetized with intravenous alfaxalone 15 min after administration of intramuscular
saline (0.5 ml/100 kg) or xylazine (0.1 mg/kg; 0.5
ml/100 kg of a 2% xylazine solution). Anesthesia induction was smooth and
orotracheal intubation was achieved in all calves. The calves anesthetized with
xylazine-alfaxalone required a smaller induction dose of alfaxalone (1.23 ± 0.17 mg/kg,
P=0.010) and accepted endotracheal intubation for a significantly
longer period (16.8 ± 7.2 min, P=0.022) than the calves anesthetized with
alfaxalone alone (2.28 ± 0.65 mg/kg 7.3 ± 1.6 min). At 5 min after induction, tachycardia
(heart rate: 166 ± 47 beats/min of heart rate), hypertension (mean arterial blood
pressure: 147 ± 81 mmHg) and hypoxemia (partial pressure of arterial blood oxygen
[PaO2]: 43 ± 10 mmHg) were observed in the calves anesthetized with
alfaxalone alone, whereas hypoxemia (PaO2: 47 ± 7 mmHg) and mild hypercapnia
(partial pressure of arterial blood carbon dioxide: 54 ± 5 mmHg) were observed in the
calves anesthetized with xylazine-alfaxalone. Premedication with xylazine provided a
sparing effect on the induction dose of alfaxalone and a prolongation of anesthetic
effect. Oxygen supplementation should be considered to prevent hypoxemia during
anesthesia.
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Affiliation(s)
- Sayed Fathi El-Hawari
- Department of Surgery, Anesthesiology, and Radiology, Faculty of Veterinary Medicine, Sohag University, Sohag 82524, Egypt
| | - Hisashi Sakata
- Department of Small Animal Clinical Sciences, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8591, Japan
| | - Norihiko Oyama
- Department of Small Animal Clinical Sciences, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8591, Japan
| | - Jun Tamura
- Department of Small Animal Clinical Sciences, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8591, Japan
| | - Chika Higuchi
- Department of Small Animal Clinical Sciences, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8591, Japan
| | - Yusuke Endo
- Department of Small Animal Clinical Sciences, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8591, Japan
| | - Kenjirou Miyoshi
- Department of Small Animal Clinical Sciences, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8591, Japan
| | - Tadashi Sano
- Department of Veterinary Nursing Science, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8591, Japan
| | - Kazuyuki Suzuki
- Department of Large Animal Clinical Sciences, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8591, Japan
| | - Kazuto Yamashita
- Department of Small Animal Clinical Sciences, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8591, Japan
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White KL, Paine S, Harris J. A clinical evaluation of the pharmacokinetics and pharmacodynamics of intravenous alfaxalone in cyclodextrin in male and female rats following a loading dose and constant rate infusion. Vet Anaesth Analg 2017; 44:865-875. [DOI: 10.1016/j.vaa.2017.01.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Franconi F, Rosano G, Campesi I. Need for gender-specific pre-analytical testing: the dark side of the moon in laboratory testing. Int J Cardiol 2014; 179:514-35. [PMID: 25465806 DOI: 10.1016/j.ijcard.2014.11.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 10/27/2014] [Accepted: 11/03/2014] [Indexed: 01/16/2023]
Abstract
Many international organisations encourage studies in a sex-gender perspective. However, research with a gender perspective presents a high degree of complexity, and the inclusion of sex-gender variable in experiments presents many methodological questions, the majority of which are still neglected. Overcoming these issues is fundamental to avoid erroneous results. Here, pre-analytical aspects of the research, such as study design, choice of utilised specimens, sample collection and processing, animal models of diseases, and the observer's role, are discussed. Artefacts in this stage of research could affect the predictive value of all analyses. Furthermore, the standardisation of research subjects according to their lifestyles and, if female, to their life phase and menses or oestrous cycle, is urgent to harmonise research worldwide. A sex-gender-specific attention to pre-analytical aspects could produce a decrease in the time for translation from the bench to bedside. Furthermore, sex-gender-specific pre-clinical pharmacological testing will enable adequate assessment of pharmacokinetic and pharmacodynamic actions of drugs and will enable, where appropriate, an adequate gender-specific clinical development plan. Therefore, sex-gender-specific pre-clinical research will increase the gender equity of care and will produce more evidence-based medicine.
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Affiliation(s)
- Flavia Franconi
- Department of Biomedical Sciences, University of Sassari, National Laboratory of Gender Medicine of the National Institute of Biostructures and Biosystems, Osilo, Sassari, Italy; Vicepresident of Basilicata Region.
| | - Giuseppe Rosano
- Cardiovascular and Cell Sciences Research Institute, St George's University of London, United Kingdom
| | - Ilaria Campesi
- Department of Biomedical Sciences, University of Sassari, National Laboratory of Gender Medicine of the National Institute of Biostructures and Biosystems, Osilo, Sassari, Italy
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