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Fernandes NS, Passos YDB, Arcoverde KN, Mouta AN, Paiva TC, Oliveira KDS, Araujo-Silva G, de Paula VV. Clinical Effects and Pharmacokinetic Profile of Intramuscular Dexmedetomidine (10 μg/kg) in Cats. Animals (Basel) 2024; 14:2274. [PMID: 39123800 PMCID: PMC11310985 DOI: 10.3390/ani14152274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2024] [Revised: 07/19/2024] [Accepted: 07/24/2024] [Indexed: 08/12/2024] Open
Abstract
This study investigated the pharmacokinetic profile of and pharmacodynamic response to dexmedetomidine administered intramuscularly (IM) at a dose of 10 μg/kg in healthy cats. Nine adult cats were evaluated before and after administration of the drug, with serial collections of plasma samples. Dexmedetomidine induced deep sedation, with a rapid onset of action and a duration of one hour, reaching a peak between 20 and 30 min after administration. The half-life (T½) was 70.2 ± 48 min, with a maximum concentration (Cmax) of 2.2 ± 1.9 ng/mL and time to reach maximum concentration (Tmax) of 26.4 ± 19.8 min. The area under the curve (AUC) was 167.1 ± 149.1 ng/mL*min, with a volume of distribution (Vd) of 2159.9 ± 3237.8 mL/kg and clearance (Cl) of 25.8 ± 33.0 mL/min/kg. There was a reduction in heart rate (HR) and respiratory rate (RR) in relation to the baseline, with a slight decrease in systolic (SBP), diastolic (DBP), and mean (MAP) blood pressure in the first hour. Blood glucose increased after 60 min. Dexmedetomidine proved to be effective and safe, with rapid absorption, metabolization, and elimination, promoting good sedation with minimal adverse effects after IM administration in healthy cats.
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Affiliation(s)
- Naftáli S. Fernandes
- Department of Animal Sciences, Semi-Arid Federal University, Mossoró 59625-900, RN, Brazil; (N.S.F.); (Y.D.B.P.); (K.N.A.); (A.N.M.); (T.C.P.); (K.D.S.O.)
| | - Yanna D. B. Passos
- Department of Animal Sciences, Semi-Arid Federal University, Mossoró 59625-900, RN, Brazil; (N.S.F.); (Y.D.B.P.); (K.N.A.); (A.N.M.); (T.C.P.); (K.D.S.O.)
| | - Kathryn N. Arcoverde
- Department of Animal Sciences, Semi-Arid Federal University, Mossoró 59625-900, RN, Brazil; (N.S.F.); (Y.D.B.P.); (K.N.A.); (A.N.M.); (T.C.P.); (K.D.S.O.)
| | - Andressa N. Mouta
- Department of Animal Sciences, Semi-Arid Federal University, Mossoró 59625-900, RN, Brazil; (N.S.F.); (Y.D.B.P.); (K.N.A.); (A.N.M.); (T.C.P.); (K.D.S.O.)
| | - Thainá C. Paiva
- Department of Animal Sciences, Semi-Arid Federal University, Mossoró 59625-900, RN, Brazil; (N.S.F.); (Y.D.B.P.); (K.N.A.); (A.N.M.); (T.C.P.); (K.D.S.O.)
| | - Kalyne D. S. Oliveira
- Department of Animal Sciences, Semi-Arid Federal University, Mossoró 59625-900, RN, Brazil; (N.S.F.); (Y.D.B.P.); (K.N.A.); (A.N.M.); (T.C.P.); (K.D.S.O.)
| | | | - Valéria Veras de Paula
- Department of Animal Sciences, Semi-Arid Federal University, Mossoró 59625-900, RN, Brazil; (N.S.F.); (Y.D.B.P.); (K.N.A.); (A.N.M.); (T.C.P.); (K.D.S.O.)
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de Sant'Ana Alves L, Arcoverde KN, de Oliveira CVA, Cavalcante JM, Araújo-Silva G, de Paula VV. Pharmacokinetics and pharmacodynamics of intravenous dexmedetomidine (2 μg∙kg -1) in dogs. Res Vet Sci 2024; 171:105229. [PMID: 38507826 DOI: 10.1016/j.rvsc.2024.105229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 02/08/2024] [Accepted: 03/12/2024] [Indexed: 03/22/2024]
Abstract
This study assessed the pharmacokinetics and pharmacodynamics of low-dose dexmedetomidine after IV bolus in dogs. Six healthy adult dogs (6.8 ± 3.0 kg) received dexmedetomidine (2 μg.kg-1 IV) over 2 min, using an infusion pump. Blood samples were collected totaling 5 h of monitoring. A validated UHPLC-MS/MS method was used to determine the plasma concentration of dexemedetomidine. For pharmacodynamics, HR, RR, oscillometric MBP, Grint END sedation score were evaluated at baseline (T0), every 3 min (T3 to T21), and after 30 (T30) and 60 (T60) minutes, with p < 0.05. T1/2 was 28.28 ± 6.14 min; the area under the curve was 467.44 ± 60.42 ng/mL/min. The total clearance was 5.46 ± 0.41 mL/min/kg, the Vdss was 146.19 ± 21.04 mL/kg, and the C max was 3.13 ± 1.15 ng/mL. HR (bpm) decreased significantly from T6 (79 ± 21) to T21 (78 ± 31) compared to T0 (116 ± 28). RR(mpm) decreased from T3 (43 ± 44) to T60 (41 ± 23), with T0 being 70 ± 48. The MBP (mmHg) increased at T18 (151 ± 34), T21 (152 ± 35), and T30 (140 ± 27), compared to T0 (111 ± 22). Sedation occurred at all times post-bolus, with a maximum peak at T12 (END 8 ± 6). The low dose of dexmedetomidine provided sedation in all animals, characterizing rapid metabolization and elimination. However, cardiovascular effects still may have negative repercussions in dogs with hemodynamic comorbidities, highlighting the caution and individualization of its use in certain patients.
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Affiliation(s)
- Larissa de Sant'Ana Alves
- Department of Animal Science, Universidade Federal Rural do Semi-Árido, 572, Rua Francisco Mota, Presidente Costa e Silva, Mossoró, RN 59625-900, Brazil
| | - Kathryn Nóbrega Arcoverde
- Department of Animal Science, Universidade Federal Rural do Semi-Árido, 572, Rua Francisco Mota, Presidente Costa e Silva, Mossoró, RN 59625-900, Brazil
| | - Caio Vinícius Almeida de Oliveira
- Department of Animal Science, Universidade Federal Rural do Semi-Árido, 572, Rua Francisco Mota, Presidente Costa e Silva, Mossoró, RN 59625-900, Brazil
| | - Jerson Marques Cavalcante
- Department of Animal Science, Universidade Federal Rural do Semi-Árido, 572, Rua Francisco Mota, Presidente Costa e Silva, Mossoró, RN 59625-900, Brazil
| | - Gabriel Araújo-Silva
- Universidade do Estado do Amapá, 650, Avenida Presidente Vargas, Centro, Macapá, AP 68.900-070, Brazil
| | - Valéria Veras de Paula
- Department of Animal Science, Universidade Federal Rural do Semi-Árido, 572, Rua Francisco Mota, Presidente Costa e Silva, Mossoró, RN 59625-900, Brazil.
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Paolini A, Vignoli M, Guerri G, Falerno I, Tamburro R, Simeoni F, Signore FD, De Bonis A, Collivignarelli F, Salvo MC, Cerasoli I. Comparison of Certain Intrarectal versus Intramuscular Pharmacodynamic Effects of Ketamine, Dexmedetomidine and Midazolam in Cats. Vet Sci 2022; 9:vetsci9100520. [PMID: 36288133 PMCID: PMC9609254 DOI: 10.3390/vetsci9100520] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 09/17/2022] [Accepted: 09/20/2022] [Indexed: 11/23/2022] Open
Abstract
The aim of this clinical trial was to evaluate the impacts of administration via the intrarectal route (IR) in cats on their heart and respiratory rates, blood pressure, body temperature, and sedation quality compared to the intramuscular route (IM). The intramuscular group (IMG) received 0.003 mg kg−1 dexmedetomidine, 2 mg kg−1 ketamine, and 0.2 mg kg−1 midazolam while the intrarectal group (IRG) protocol was 0.003 mg kg−1 dexmedetomidine, 4 mg kg−1 ketamine, and 0.4 mg kg−1 midazolam. Cardiorespiratory values, temperature, and sedation score were measured 2 min after administration and then every 5 min up to the 40th minute. Cats belonging to IRG reacted less strongly to the drug, as opposed to those receiving intramuscular administration (2/10 in IRG vs. 8/10 in IMG). Average time between drug administration and standing position was 44.9 ± 5.79 in IRG and 57 ± 9.88 min in IMG. In IRG, maintenance of SpO₂ values is >95% at each time point. Median and range peak of sedation {7 (5)} in IMG occurs at 20th, 25th, and 30th minutes post drug administration while was lower in IRG. Cardiorespiratory values were slightly lower in IMG than in IRG, but always constant in both treatments. Temperature did not differ between groups. At this dosage, although sedation score was higher in IMG, intrarectal route could be efficacious for performing minimally invasive clinical and diagnostic procedures in cats.
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Affiliation(s)
- Andrea Paolini
- Faculty of Veterinary Medicine, University of Teramo, Località Piano D’Accio, 64100 Teramo, Italy
- Correspondence:
| | - Massimo Vignoli
- Faculty of Veterinary Medicine, University of Teramo, Località Piano D’Accio, 64100 Teramo, Italy
| | - Giulia Guerri
- Faculty of Veterinary Medicine, University of Teramo, Località Piano D’Accio, 64100 Teramo, Italy
| | - Ilaria Falerno
- Faculty of Veterinary Medicine, University of Teramo, Località Piano D’Accio, 64100 Teramo, Italy
| | - Roberto Tamburro
- Faculty of Veterinary Medicine, University of Teramo, Località Piano D’Accio, 64100 Teramo, Italy
| | - Francesco Simeoni
- Faculty of Veterinary Medicine, University of Teramo, Località Piano D’Accio, 64100 Teramo, Italy
| | - Francesca Del Signore
- Faculty of Veterinary Medicine, University of Teramo, Località Piano D’Accio, 64100 Teramo, Italy
| | - Andrea De Bonis
- Faculty of Veterinary Medicine, University of Teramo, Località Piano D’Accio, 64100 Teramo, Italy
| | | | - Maria Cristina Salvo
- Faculty of Veterinary Medicine, University of Teramo, Località Piano D’Accio, 64100 Teramo, Italy
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Physiological and Clinical Responses in Pigs in Relation to Plasma Concentrations during Anesthesia with Dexmedetomidine, Tiletamine, Zolazepam, and Butorphanol. Animals (Basel) 2021; 11:ani11061482. [PMID: 34063808 PMCID: PMC8224090 DOI: 10.3390/ani11061482] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/16/2021] [Accepted: 05/17/2021] [Indexed: 12/17/2022] Open
Abstract
Simple Summary Reliable protocols are needed for short-term anesthesia in pigs. The study’s aim is to identify an anesthetic procedure that, without the use of sophisticated equipment, ensures an acceptable depth and length of anesthesia, a regular spontaneous breathing pattern, and a stable hemodynamic condition for the animal. A total of 12 pigs were given a single intramuscular injection of dexmedetomidine, tiletamine, zolazepam, and butorphanol. To investigate the possibility of prolonging the anesthesia, six of the pigs also received an intravenous dose of the drug combination after one hour. Physiological and clinical responses and drug plasma concentrations were examined. The main results suggest that intramuscular administration of the drug combination provides up to two hours of anesthesia with stable physiological parameters and an acceptable level of analgesia. An intravenous administration of one-third of the original dosage prolonged the anesthesia for another 30 min. Since the pigs were able to breathe spontaneously, none of them were intubated. The study also provides new information about each drug’s plasma concentrations and the impact of the drug combination in pigs. This technique can be used to perform nonsurgical operations or transports when short-term anesthesia is required. Abstract Reliable protocols for short-term anesthetics are essential to safeguard animal welfare during medical investigations. The aim of the study was to assess the adequacy and reliability of an anesthetic protocol and to evaluate physiological and clinical responses, in relation to the drug plasma concentrations, for pigs undergoing short-term anesthesia. A second aim was to see whether an intravenous dosage could prolong the anesthesia. The anesthesia was induced by an intramuscular injection of dexmedetomidine, tiletamine-zolazepam, and butorphanol in 12 pigs. In six of the pigs, a repeated injection intravenously of one-third of the initial dose was given after one hour. The physiological and clinical effects from induction to recovery were examined. Plasma concentrations of the drugs were analyzed and pharmacokinetic parameters were calculated. Each drug’s absorption and time to maximal concentration were rapid. All pigs were able to maintain spontaneous respiration. The route of administration did not alter the half-life of the drug. The results suggest that intramuscular administration of the four-drug combination provides up to two hours of anesthesia with stable physiological parameters and an acceptable level of analgesia while maintaining spontaneous respiration. A repeated intravenous injection may be used to extend the time of anesthesia by 30 min.
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Guedes A, Knych H, Tucker L, Almeida DC, Baldo CF, Wendt-Hornickle E, Allweiler S. Pharmacokinetics and clinical effects of xylazine and dexmedetomidine in horses recovering from isoflurane anesthesia. J Vet Pharmacol Ther 2020; 43:369-376. [PMID: 32166760 DOI: 10.1111/jvp.12855] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 01/29/2020] [Accepted: 02/23/2020] [Indexed: 12/01/2022]
Abstract
This study determined the pharmacokinetics and compared the clinical effects of xylazine and dexmedetomidine in horses recovering from isoflurane anesthesia. Six healthy horses aged 8.5 ± 3 years and weighing 462 ± 50 kg were anesthetized with isoflurane for 2 hr under standard conditions on two occasions one-week apart. In recovery, horses received 200 μg/kg xylazine or 0.875 μg/kg dexmedetomidine intravenously and were allowed to recover without assistance. These doses were selected because they have been used for postanesthetic sedation in clinical and research studies. Serial venous blood samples were collected for quantification of xylazine and dexmedetomidine, and the pharmacokinetic parameters were calculated. Two individuals blinded to treatment identity evaluated recovery quality with a visual analog scale. Times to stand were recorded. Results (mean ± SD) were compared using paired t tests or Wilcoxon signed-ranked test with p < .05 considered significant. Elimination half-lives (62.7 ± 21.8 and 30.1 ± 8 min for xylazine and dexmedetomidine, respectively) and steady-state volumes of distribution (215 ± 123 and 744 ± 403 ml/kg) were significantly different between xylazine and dexmedetomidine, whereas clearances (21.1 ± 17.3 and 48.6 ± 28.1 ml/minute/kg), times to stand (47 ± 24 and 53 ± 12 min) and recovery quality (51 ± 24 and 61 ± 22 mm VAS) were not significantly different. When used for postanesthetic sedation following isoflurane anesthesia in healthy horses, dexmedetomidine displays faster plasma kinetics but is not associated with faster recoveries compared to xylazine.
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Affiliation(s)
- Alonso Guedes
- Veterinary Clinical Sciences Department, College of Veterinary Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Heather Knych
- K. L. Maddy Equine Analytical Chemistry Laboratory, School of Veterinary Medicine, University of California, Davis, CA, USA
| | - Laura Tucker
- Veterinary Clinical Sciences Department, College of Veterinary Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Daniel C Almeida
- Veterinary Clinical Sciences Department, College of Veterinary Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Caroline F Baldo
- Veterinary Clinical Sciences Department, College of Veterinary Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Erin Wendt-Hornickle
- Veterinary Clinical Sciences Department, College of Veterinary Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Sandra Allweiler
- Veterinary Clinical Sciences Department, College of Veterinary Medicine, University of Minnesota, Minneapolis, MN, USA
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Martin-Flores M, Sakai DM, Honkavaara J, Campoy L. Hemodynamic effects of low-dose atipamezole in isoflurane-anesthetized cats receiving an infusion of dexmedetomidine. J Feline Med Surg 2018; 20:571-577. [PMID: 28766985 PMCID: PMC11104072 DOI: 10.1177/1098612x17722265] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Objectives The objective of this study was to evaluate the cardiovascular effects of low-dose atipamezole administered intravenously to isoflurane-anesthetized cats receiving dexmedetomidine. We hypothesized that atipamezole would increase heart rate (HR) and reduce arterial blood pressure in isoflurane-anesthetized cats receiving dexmedetomidine. Methods Six healthy adult domestic shorthair cats were anesthetized with isoflurane and instrumented for direct arterial pressures and cardiac output (CO) measurements. The cats received a target-controlled infusion of dexmedetomidine (target plasma concentration 10 ng/ml) for 30 mins before administration of atipamezole. Two sequential doses of atipamezole (15 and 30 μg/kg IV) were administered at least 20 mins apart, during dexmedetomidine administration. The effects of dexmedetomidine and each dose of atipamezole on HR, mean arterial blood pressure (MAP), CO and systemic vascular resistance (SVR) were documented. Results Dexmedetomidine reduced the HR by 22%, increased MAP by 78% (both P ⩽0.01), decreased CO by 48% and increased SVR by 58% (both P ⩽0.0003). Administration of atipamezole 15 and 30 μg/kg intravenously increased HR by 8% ( P = 0.006) and 4% ( P = 0.1), respectively. MAP decreased by 39% and 47%, respectively (both P ⩽0.004). Atipamezole 30 μg/kg returned CO and SVR to baseline values. Conclusions and relevance Low doses of atipamezole (15 and 30 μg/kg) administered intravenously to anesthetized cats decreased arterial blood pressure with only marginal increases in HR. Atipamezole 30 μg/kg restored CO and SVR to baseline values before dexmedetomidine administration.
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Affiliation(s)
- Manuel Martin-Flores
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Daniel M Sakai
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Juhana Honkavaara
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Finland
| | - Luis Campoy
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
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Pypendop BH, Honkavaara J, Ilkiw JE. Pharmacokinetics of dexmedetomidine, MK-467 and their combination following intramuscular administration in male cats. Vet Anaesth Analg 2017; 44:823-831. [DOI: 10.1016/j.vaa.2017.02.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Revised: 02/20/2017] [Accepted: 02/21/2017] [Indexed: 10/19/2022]
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Brynildsen JK, Hsu LM, Ross TJ, Stein EA, Yang Y, Lu H. Physiological characterization of a robust survival rodent fMRI method. Magn Reson Imaging 2016; 35:54-60. [PMID: 27580522 DOI: 10.1016/j.mri.2016.08.010] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 08/13/2016] [Accepted: 08/20/2016] [Indexed: 10/21/2022]
Abstract
Anesthetics are commonly used in preclinical functional MRI studies. It is well-appreciated that proper choice of anesthetics is of critical importance for maintaining a physiologically normal range of autonomic functioning. A recent study, using a low dose of dexmedetomidine (active isomer of medetomidine) in combination with a low dose of isoflurane, suggested stable measurements across repeated fMRI experiments in individual animals with each session lasting up to several hours. The rat default mode network has been successfully identified using this preparation, indicating that this protocol minimally disturbs brain network functions. However, medetomidine is known to cause peripheral vasoconstriction, respiratory suppression, and bradycardia, each of which could independently confound the BOLD signal. The goal of this study was to systematically characterize physiological conditions for fMRI experiments under this anesthetic regimen. To this end, we acquired somatosensory stimulation "task-evoked" and resting-state fMRI to evaluate the integrity of neurovascular coupling and brain network function during three time windows (0-30min, 30-90min, and 90-150min) following dexmedetomidine initiation. Results demonstrate that both evoked BOLD response and resting-state fMRI signal remained stable during the 90-150min time window, while autonomic physiological parameters maintained near-normal conditions during this period. Our data suggest that using a spontaneously-inhaled, low dose of isoflurane in combination with a continuous low dose of dexmedetomidine is a viable option for longitudinal imaging studies in rats.
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Affiliation(s)
- Julia K Brynildsen
- Neuroimaging Research Branch, National Institute on Drug Abuse, Intramural Research Program, 251 Bayview Blvd, Suite 200, Baltimore, MD, USA
| | - Li-Ming Hsu
- Neuroimaging Research Branch, National Institute on Drug Abuse, Intramural Research Program, 251 Bayview Blvd, Suite 200, Baltimore, MD, USA
| | - Thomas J Ross
- Neuroimaging Research Branch, National Institute on Drug Abuse, Intramural Research Program, 251 Bayview Blvd, Suite 200, Baltimore, MD, USA
| | - Elliot A Stein
- Neuroimaging Research Branch, National Institute on Drug Abuse, Intramural Research Program, 251 Bayview Blvd, Suite 200, Baltimore, MD, USA
| | - Yihong Yang
- Neuroimaging Research Branch, National Institute on Drug Abuse, Intramural Research Program, 251 Bayview Blvd, Suite 200, Baltimore, MD, USA
| | - Hanbing Lu
- Neuroimaging Research Branch, National Institute on Drug Abuse, Intramural Research Program, 251 Bayview Blvd, Suite 200, Baltimore, MD, USA.
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Messenger KM, Hopfensperger M, Knych HK, Papich MG. Pharmacokinetics of detomidine following intravenous or oral-transmucosal administration and sedative effects of the oral-transmucosal treatment in dogs. Am J Vet Res 2016; 77:413-20. [DOI: 10.2460/ajvr.77.4.413] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
OBJECTIVE To determine the pharmacokinetics of detomidine hydrochloride administered IV (as an injectable formulation) or by the oral-transmucosal (OTM) route (as a gel) and assess sedative effects of the OTM treatment in healthy dogs.
ANIMALS 12 healthy adult dogs.
PROCEDURES In phase 1, detomidine was administered by IV (0.5 mg/m2) or OTM (1 mg/m2) routes to 6 dogs. After a 24-hour washout period, each dog received the alternate treatment. Blood samples were collected for quantification via liquid chromatography with mass spectrometry and pharmacokinetic analysis. In phase 2, 6 dogs received dexmedetomidine IV (0.125 mg/m2) or detomidine gel by OTM administration (0.5 mg/m2), and sedation was measured by a blinded observer using 2 standardized sedation scales while dogs underwent jugular catheter placement. After a l-week washout period, each dog received the alternate treatment.
RESULTS Median maximum concentration, time to maximum concentration, and bioavailability for detomidine gel following OTM administration were 7.03 ng/mL, 1.00 hour, and 34.52%, respectively; harmonic mean elimination half-life was 0.63 hours. All dogs were sedated and became laterally recumbent with phase 1 treatments. In phase 2, median global sedation score following OTM administration of detomidine gel was significantly lower (indicating a lesser degree of sedation) than that following IV dexmedetomidine treatment; however, total sedation score during jugular vein catheterization did not differ between treatments. The gel was subjectively easy to administer, and systemic absorption was sufficient for sedation.
CONCLUSIONS AND CLINICAL RELEVANCE Detomidine gel administered by the OTM route provided sedation suitable for a short, minimally invasive procedure in healthy dogs.
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Pypendop BH, Honkavaara J, Ilkiw JE. Pharmacokinetics of dexmedetomidine, MK-467, and their combination following intravenous administration in male cats. J Vet Pharmacol Ther 2016; 39:460-8. [DOI: 10.1111/jvp.12302] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2015] [Accepted: 01/29/2016] [Indexed: 01/11/2023]
Affiliation(s)
- B. H. Pypendop
- Department of Surgical and Radiological Sciences; School of Veterinary Medicine; University of California; Davis CA USA
| | - J. Honkavaara
- Department of Equine and Small Animal Medicine; Faculty of Veterinary Medicine; University of Helsinki; Helsinki Finland
| | - J. E. Ilkiw
- Department of Surgical and Radiological Sciences; School of Veterinary Medicine; University of California; Davis CA USA
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Pypendop BH, Ilkiw JE. Relationship between plasma dexmedetomidine concentration and sedation score and thermal threshold in cats. Am J Vet Res 2014; 75:446-52. [PMID: 24762016 DOI: 10.2460/ajvr.75.5.446] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To characterize the relationship between plasma dexmedetomidine concentration and the temperature difference between the thermal threshold and skin temperature (ΔT) and between plasma dexmedetomidine concentration and sedation score in healthy cats. ANIMALS 5 healthy adult spayed female cats. PROCEDURES Cats received IV administrations of saline (0.9% NaCl) solution, dexmedetomidine (5, 20, or 50 μg/kg), or acepromazine (0.1 mg/kg). Blood samples were collected and thermal threshold and sedation score were determined before and at various times up to 8 hours after drug administration. In addition, cats received an IV infusion of dexmedetomidine that targeted a concentration achieving 99% of the maximum effect on ΔT. RESULTS No change in ΔT over time was found for the saline solution and acepromazine treatments; ΔT increased for 45 minutes when cats received dexmedetomidine at 5 and 20 μg/kg and for 180 minutes when cats received dexmedetomidine at 50 μg/kg. No change in sedation score over time was found for saline solution. Sedation score increased for 120 minutes after cats received acepromazine and for 60, 120, and 180 minutes after cats received dexmedetomidine at 5, 20, and 50 μg/kg, respectively. The plasma dexmedetomidine concentration-effect relationships for the effect on ΔT and sedation score were almost identical. The plasma dexmedetomidine concentration after infusion was lower than targeted, and ΔT was not significantly affected. CONCLUSIONS AND CLINICAL RELEVANCE Dexmedetomidine administration to cats resulted in thermal analgesia and also profound sedation. These data may be useful for predicting the course of thermal analgesia and sedation after dexmedetomidine administration to cats.
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Affiliation(s)
- Bruno H Pypendop
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616
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