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Clark TP, Linton DD, Freise KJ, Reinemeyer C, Newkirk KM, Aulbach A, Lin T. Margin of safety of extended‐duration transdermal buprenorphine solution following multiple‐dose administrations to cats. J Vet Pharmacol Ther 2022; 45 Suppl 1:S67-S84. [DOI: 10.1111/jvp.13051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 02/05/2022] [Accepted: 03/06/2022] [Indexed: 11/27/2022]
Affiliation(s)
| | | | | | | | - Kim M. Newkirk
- College of Veterinary Medicine, Biomedical and Diagnostic Sciences Department University of Tennessee Knoxville Tennessee USA
| | | | - Ting‐Li Lin
- Nexcyon Pharmaceuticals, Inc. Madison Wisconsin USA
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Clark TP. The history and pharmacology of buprenorphine: New advances in cats. J Vet Pharmacol Ther 2022; 45 Suppl 1:S1-S30. [DOI: 10.1111/jvp.13073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 04/19/2022] [Accepted: 05/14/2022] [Indexed: 11/30/2022]
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Freise KJ, Reinemeyer C, Warren K, Lin TL, Clark TP. Single-dose pharmacokinetics and bioavailability of a novel extended duration transdermal buprenorphine solution in cats. J Vet Pharmacol Ther 2022; 45 Suppl 1:S31-S39. [PMID: 35790014 DOI: 10.1111/jvp.13044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 01/12/2022] [Accepted: 01/22/2022] [Indexed: 11/29/2022]
Abstract
A novel transdermal buprenorphine solution (TBS) was developed for evaluation in order to make available an extended duration opioid analgesic for cats. Healthy adult cats were administered a single TBS dose of 10 mg (1.57-4.35 mg/kg), 30 mg (4.72-13.0 mg/kg), or 50 mg (7.87-21.7 mg/kg) (4 cats per group) applied topically to the unclipped dorsal cervical skin and plasma buprenorphine concentrations were evaluated through 7 days. To determine the absolute bioavailability of TBS, healthy cats were administered single TBS dose of 20 mg (3.33-4.76 mg/kg) or 0.05 mg (0.008-0.011 mg/kg) IV buprenorphine (6 cats per group). The mean ± standard deviation maximum plasma buprenorphine concentrations (Cmax ) were 10.5 ± 6.28, 18.6 ± 8.68, and 22.5 ± 4.47 ng/ml following 10, 30, and 50 mg doses, respectively, with the time of Cmax occurrence (tmax ) typically occurring at 2-12 h post-dosing. Mean plasma buprenorphine terminal half-lives ranged between 78.3 and 91.2 h. Increasing the dose threefold and fivefold from the 10 mg dose increased the exposure by 2.8- and 3.6-fold, respectively, indicating that plasma buprenorphine exposure increased in a less than proportional manner at doses >30 mg. Transient sedation, mydriasis, and euphoria were observed within 4 h post-dosing. Mean rectal temperatures were increased 0.6-0.9°C greater than baseline (37.4-37.8°C) through 168 h post-dosing. The absolute bioavailability was 16.0% (90% CI: [11.8%-21.7%]). Flip-flop pharmacokinetics were observed with a terminal elimination half-life of 0.82 ± 0.13 and 64.9 ± 15.0 h for IV buprenorphine and 20 mg of TBS, respectively. A single administration of TBS over a range of doses resulted in extended plasma buprenorphine concentrations and opioid physiological and behavioral effects.
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Affiliation(s)
| | - Craig Reinemeyer
- East Tennessee Clinical Research, Inc., Rockwood, Tennessee, USA
| | | | - Ting-Li Lin
- Nexcyon Pharmaceuticals, Inc., Madison, Wisconsin, USA
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Clark TP, Linton DD, Freise KJ, Lin TL. Multicentered masked placebo-controlled phase 3 clinical study of an extended duration transdermal buprenorphine solution for post-operative pain in cats. J Vet Pharmacol Ther 2022; 45 Suppl 1:S52-S66. [PMID: 35790011 DOI: 10.1111/jvp.13060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 03/28/2022] [Accepted: 03/29/2022] [Indexed: 01/12/2023]
Abstract
A prospective, double masked, placebo-controlled, multicentered phase 3 clinical study was conducted to evaluate the safety and effectiveness of transdermal buprenorphine solution (TBS) for the control of post-operative pain in cats. A total of 228 cats from 12 US investigational sites met the enrollment criteria of which 107 placebo- and 112 TBS-treated cats were included into the per protocol efficacy analysis. The dose of TBS was 8 mg (0.4 ml) to cats 1.2 to 3 kilograms and 20 mg (1 ml) to cats >3 to 7.5 kilograms applied topically to the dorsal unclipped cervical skin 1-2 h prior to the undergoing elective surgical reproductive sterilization in conjunction with forelimb onychectomy. Interactive pain assessments and physiological variables were quantified through 96 h following recovery from anesthesia, and rescue analgesia was administered any time that pain control was scored inadequate. Cats requiring rescue analgesia or experiencing an adverse event suspected to be treatment related were considered treatment failures. Sixty-five and 23 cats were considered treatment failures in the placebo and TBS groups, respectively, with most occurring on the day of surgery. The treatment success rates were 0.40 (95% confidence interval [CI]: [0.28-0.53]) and 0.81 (95% CI: [0.70-0.89]) in the placebo and TBS groups, respectively, and the difference was significant (p < .05). Adverse events occurred at a similar frequency and were not clinically meaningful in either treatment group. The post-operative body temperatures over the duration of the study were on average 0.35 (95% CI: [0.20-0.50]) °C higher than baseline in TBS-treated cats and were not clinically meaningful, an observation typical of opioids in cats. These results serve as substantial evidence that TBS is safe and effective for the control of orthopedic and soft tissue post-operative pain in cats when a single topical dose is applied 1-2 h prior to surgery.
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Affiliation(s)
| | - Deborah D Linton
- Nexcyon Pharmaceuticals, Inc., Madison, Wisconsin, USA
- Deborah D. Linton, DL Veterinary Consulting, LLC, Florida, USA
| | - Kevin J Freise
- Nexcyon Pharmaceuticals, Inc., Madison, Wisconsin, USA
- Kevin J. Freise, AbbVie Inc., North Chicago, Illinois, USA
| | - Ting-Li Lin
- Nexcyon Pharmaceuticals, Inc., Madison, Wisconsin, USA
- Ting-Li Lin, Briostat, LLC, Madison, Wisconsin, USA
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Clark TP, Linton DD, Freise KJ, Lin TL. Multicentered masked placebo-controlled phase 2 clinical study of an extended duration transdermal buprenorphine solution for postoperative pain in cats. J Vet Pharmacol Ther 2022; 45 Suppl 1:S40-S51. [PMID: 35790010 DOI: 10.1111/jvp.13059] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 03/28/2022] [Accepted: 03/29/2022] [Indexed: 01/12/2023]
Abstract
A prospective, double-masked, placebo-controlled, multicentered phase 2 clinical study was conducted to select the transdermal buprenorphine solution (TBS) dosage for the control of postoperative pain in cats. One-hundred fifteen (115) cats were randomized to a single topical dose of placebo solution, low-TBS dosage (1.91-2.07 mg/kg) or high-TBS dosage (4.27-4.88 mg/kg) prior to surgical reproductive sterilization in conjunction with forelimb onychectomy. The low- and high-TBS doses were applied 2-4 and 1-2 hours prior to surgery. Interactive pain assessments and physiological variables were quantified through 96 hours post-anesthetic recovery and rescue analgesia was administered any time that analgesia was considered inadequate. Cats requiring rescue analgesia were considered treatment failures. The estimated overall treatment success rates from generalized linear mixed effects model analysis were 0.10 (95% CI: [0.02-0.36]), 0.56 (95% CI: [0.25-0.83]), 0.71 (95% CI: [0.38-0.91]) in the placebo-, low-, and high-TBS dose groups, respectively. Success rates for both TBS treatment groups were superior to placebo. Adverse events were infrequent in all treatment groups although the postoperative body temperatures over the duration of the study were on average 0.31 (95% CI: [0.08-0.55]) and 0.30 (95% CI: [0.05-0.53]) °C higher in low- and high-TBS dose cats, respectively, compared to placebo. It is concluded that both the low- and high-TBS dosages were safe and effective. The high-TBS dosage resulted in a greater proportion of treatment successes over 96 h, had a more acceptable preoperative application time of 1-2 h prior to surgery, and was therefore selected for further study.
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Affiliation(s)
| | - Deborah D Linton
- Nexcyon Pharmaceuticals, Inc., Madison, Wisconsin, USA
- Deborah D. Linton, DL Veterinary Consulting, LLC, Rotonda West, Florida, USA
| | - Kevin J Freise
- Nexcyon Pharmaceuticals, Inc., Madison, Wisconsin, USA
- Kevin J. Freise, AbbVie Inc., North Chicago, Illinois, USA
| | - Ting-Li Lin
- Nexcyon Pharmaceuticals, Inc., Madison, Wisconsin, USA
- Ting-Li Lin, Briostat, LLC, Madison, Wisconsin, USA
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Moreno KL, Scallan EM, Monteiro BP, Steagall PV, Simon BT. The thermal antinociceptive effects of a high-concentration formulation of buprenorphine alone or followed by hydromorphone in conscious cats. Vet Anaesth Analg 2021; 48:570-576. [PMID: 33926823 DOI: 10.1016/j.vaa.2021.03.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 02/26/2021] [Accepted: 03/05/2021] [Indexed: 10/21/2022]
Abstract
OBJECTIVE To evaluate the thermal antinociceptive effects of a high-concentration formulation of buprenorphine alone or followed by hydromorphone in conscious cats. STUDY DESIGN Randomized, blinded, placebo-controlled crossover study design. ANIMALS A total of six purpose-bred, adult female ovariohysterectomized Domestic Short Hair cats. METHODS Cats were allocated into three treatments each consisting of two injections, subcutaneous then intravenous (IV) administration, 2 hours apart: treatment SS, two injections of 0.9% saline; treatment BS, buprenorphine (0.24 mg kg-1, 1.8 mg mL-1) and saline; and treatment BH, buprenorphine (0.24 mg kg-1) and hydromorphone (0.1 mg kg-1). Skin temperature (ST) and thermal threshold (TT) were recorded before (baseline) and for 24 hours following first injection. TT data were analyzed using mixed linear models and a Benjamini-Hochberg sequential adjustment procedure (p < 0.05). RESULTS There were no significant differences among treatments for baseline ST and TT values, treatment SS over time and between treatments BS and BH. Compared with baseline, TT was significantly increased at all time points in treatments BH and BS except at 2 hours in treatment BS. TT was significantly higher than SS at 3-18 hours and 4-12 hours for treatments BS and BH, respectively. Maximal increases in TT were 47.5 °C at 2 hours, 53.9 °C at 3 hours and 52.4 °C at 6 hours in treatments SS, BS and BH, respectively. CONCLUSIONS AND CLINICAL RELEVANCE Administration of IV hydromorphone following high-concentration buprenorphine provided no additional antinociception and decreased the duration of effect when compared with high-concentration buprenorphine alone. Alternative analgesics should be considered if additional analgesia is required after administration of high-concentration buprenorphine.
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Affiliation(s)
- Kara L Moreno
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA
| | - Elizabeth M Scallan
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA
| | - Beatriz P Monteiro
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Université de Montréal, Saint-Hyacinthe, QC, Canada
| | - Paulo V Steagall
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Université de Montréal, Saint-Hyacinthe, QC, Canada
| | - Bradley T Simon
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA.
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Lord S, Girling SJ, Eivers C, Pizzi R, Panti A. Presumptive buprenorphine associated intraoperative apnoea and prolonged recovery in a giant panda (
Ailuropoda melanoleuca
) during castration for testicular neoplasia. VETERINARY RECORD CASE REPORTS 2020. [DOI: 10.1136/vetreccr-2019-001063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- Samuel Lord
- Clinical StudiesThe University of Edinburgh Royal Dick School of Veterinary StudiesEaster BushUK
| | | | - Caroline Eivers
- Diagnostic ImagingUniversity of Glasgow College of Medical Veterinary and Life SciencesGlasgowUK
| | - Romain Pizzi
- Wildlife Surgery InternationalRoslinMidlothianUK
| | - Ambra Panti
- AnaesthesiaUniversity of Edinburgh Royal Dick School of Veterinary StudiesEdinburghMidlothianUK
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Leedham R, White KL, Yates D, Brown L. Comparison of two high doses of subcutaneous buprenorphine in cats undergoing ovariohysterectomy. ACTA ACUST UNITED AC 2019. [DOI: 10.12968/coan.2019.0036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Objectives: The aim of the study was to evaluate the analgesia and recovery effects of two doses (0.12 mg/kg and 0.24 mg/kg) of subcutaneous buprenorphine in cats undergoing ovariohysterectomy. Methods: This was an assessor-blinded, randomised, clinical study. A total of 83 cats were recruited and randomly allocated to receive 0.12 mg/kg buprenorphine or 0.24 mg/kg buprenorphine subcutaneously, followed 30 minutes later by 40 μg/kg medetomidine intramuscularly. Anaesthesia was induced with intravenous alfaxalone to effect and maintained with isoflurane in oxygen. All cats received meloxicam before surgery. Temperament score, quality of sedation, induction of anaesthesia, dose of alfaxalone and recovery were scored using simple descriptive scales. Atipamazole was administered following surgery. Physiological variables during anaesthesia were recorded. Cats were assessed postoperatively by the same blinded observer at 2, 4 and 24 hours using a modified Colorado Feline Acute Pain scale. The presence or absence of mydriasis was noted. Results: No significant differences were identified between groups. Three cats in the 0.12 mg/kg group and four in the 0.24 mg/kg group required rescue analgesia. Mydriasis persisting for at least 24 hours was evident in 75 cats. Conclusions and relevance: No differences in analgesia were detected between groups with these protocols; mydriasis was common in both groups.
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Affiliation(s)
- Rosa Leedham
- RSPCA Greater Manchester Animal Hospital, 411 Eccles New Rd, Salford M5 5NN, UK
| | - Kate L White
- School of Veterinary Medicine and Science, University of Nottingham, Loughborough UK
| | - David Yates
- RSPCA Greater Manchester Animal Hospital, 411 Eccles New Rd, Salford M5 5NN, UK
| | - Lauren Brown
- School of Veterinary Medicine and Science, University of Nottingham, Loughborough UK
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Schroers M, Meyer-Lindenberg A, Reese S, Dobenecker B, Pieper K. Pharmacokinetics of low-dose and high-dose buprenorphine in cats after rectal administration of different formulations. J Feline Med Surg 2019; 21:938-943. [PMID: 30427272 PMCID: PMC11132234 DOI: 10.1177/1098612x18810933] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVES A prospective experimental study was performed in nine young healthy cats to investigate a pharmacokinetic profile and the clinical relevance of rectally administered buprenorphine. Rectal pH value was measured in all nine cats. METHODS Blood was collected 15, 30, 60, 90, 120, 240 and 480 mins and 24 h after the rectal administration of a suppository and a gel at doses between 0.02 mg/kg and 0.1 mg/kg buprenorphine to determine the plasma concentration of buprenorphine. Rectal pH was measured with pH paper. RESULTS Upon pharmacokinetic non-compartment analysis of high-dose buprenorphine (0.1 mg/kg), average maximal plasma concentration was found to be 1.13 ng/ml, time to maximal plasma concentration was 45 mins and area under the plasma concentration-time curve was 94.19 ng*min/ml, representing low but potential bioavailability. Mean residual time was 152.2 mins and the half-life was 92.6 mins. A wide range of plasma concentrations within the cohort was measured and two of the cats had to be excluded from statistical analysis owing to incomplete uptake. Vital parameters of all cats were considered to be normal but three of the cats showed mydriasis up to 8 h after application. After the administration of a low-dose suppository or a rectal gel (0.02 mg/kg) within pilot studies, no buprenorphine was detected in cat plasma. Rectal pH in all cats was between 7.7 and 8. CONCLUSIONS AND RELEVANCE The rectal application of buprenorphine at a dose of 0.1 mg/kg revealed a potential but weak uptake in cats. Regarding effective concentrations in previous pharmacokinetic investigations, rectal administration is currently not recommended for good provision of opioid analgesia in cats. Pharmacological investigations of formulation and galenics in order to improve the rectal bioavailability of buprenorphine remain to be clarified before further dose-finding and pharmacokinetic/pharmacodynamic studies are performed.
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Affiliation(s)
- Maike Schroers
- Department of Small Animal Surgery, Faculty of Veterinary Medicine, Ludwig Maximilians University Munich, Munich, Germany
| | - Andrea Meyer-Lindenberg
- Department of Small Animal Surgery, Faculty of Veterinary Medicine, Ludwig Maximilians University Munich, Munich, Germany
| | - Sven Reese
- Department of Veterinary Science, Faculty of Veterinary Medicine, Ludwig Maximilians University Munich, Munich, Germany
| | - Britta Dobenecker
- Department of Veterinary Science, Faculty of Veterinary Medicine, Ludwig Maximilians University Munich, Munich, Germany
| | - Korbinian Pieper
- Department of Small Animal Surgery, Faculty of Veterinary Medicine, Ludwig Maximilians University Munich, Munich, Germany
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Gleeson MD, Guzman DSM, Knych HK, Kass PH, Drazenovich TL, Hawkins MG. Pharmacokinetics of a concentrated buprenorphine formulation in red-tailed hawks (Buteo jamaicensis). Am J Vet Res 2017; 79:13-20. [PMID: 29287158 DOI: 10.2460/ajvr.79.1.13] [Citation(s) in RCA: 7] [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 determine the pharmacokinetics and sedative effects of 2 doses of a concentrated buprenorphine formulation after SC administration to red-tailed hawks (Buteo jamaicensis). ANIMALS 6 adult red-tailed hawks. PROCEDURES Concentrated buprenorphine (0.3 mg/kg, SC) was administered to all birds. Blood samples were collected at 10 time points over 24 hours after drug administration to determine plasma buprenorphine concentrations. After a 4-week washout period, the same birds received the same formulation at a higher dose (1.8 mg/kg, SC), and blood samples were collected at 13 time points over 96 hours. Hawks were monitored for adverse effects and assigned agitation-sedation scores at each sample collection time. Plasma buprenorphine concentrations were quantified by liquid chromatography-tandem mass spectrometry. RESULTS Mean time to maximum plasma buprenorphine concentration was 7.2 minutes and 26.1 minutes after administration of the 0.3-mg/kg and 1.8-mg/kg doses, respectively. Plasma buprenorphine concentrations were > 1 ng/mL for mean durations of 24 and 48 hours after low- and high-dose administration, respectively. Mean elimination half-life was 6.23 hours for the low dose and 7.84 hours for the high dose. Mean agitation-sedation scores were higher (indicating some degree of sedation) than the baseline values for 24 hours at both doses. No clinically important adverse effects were observed. CONCLUSIONS AND CLINICAL RELEVANCE Concentrated buprenorphine was rapidly absorbed, and plasma drug concentrations considered to have analgesic effects in other raptor species were maintained for extended periods. Most birds had mild to moderate sedation. Additional studies are needed to evaluate the pharmacodynamics of these doses of concentrated buprenorphine in red-tailed hawks.
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Simon BT, Steagall PV. The present and future of opioid analgesics in small animal practice. J Vet Pharmacol Ther 2016; 40:315-326. [DOI: 10.1111/jvp.12377] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 09/25/2016] [Indexed: 11/30/2022]
Affiliation(s)
- B. T. Simon
- Department of Small Animal Clinical Sciences; College of Veterinary Medicine and Biomedical Sciences; Texas A&M University; College Station TX USA
| | - P. V. Steagall
- Department of Clinical Sciences; Faculty of Veterinary Medicine; Université de Montréal; Saint-Hyacinthe QC Canada
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Srinivas NR. Relationship Between Buprenorphine Dosing and Triglyceride Lowering and creatine kinase [corrected] Elevation in Felines: Possible Human Implications. J Pain Palliat Care Pharmacother 2016; 30:49-52. [PMID: 26861654 DOI: 10.3109/15360288.2015.1134751] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Recently published feline data suggest that high doses of buprenorphine can elevate creatine kinase (CK) [corrected] and profoundly influence triglyceride levels in an inverted dose versus effect relationship. This intriguing observation in felines, hitherto not documented for buprenorphine, should be considered in human situations for any trends of translatability. The report evaluates the observed effects in domestic cats and what is known about buprenorphine in human subjects. Based on the objective assessment, the following are deduced: (a) although elevated CK levels is a nonissue in humans, one needs to pay attention especially when buprenorphine is used at the high end of therapeutic dose range in the presence of drugs that can impair the hepatic metabolism of buprenorphine; and (b) the potential for triglyceride lowering can be easily confirmed in human trials, and since it may occur at the relevant therapeutic doses of buprenorphine, it may be beneficial in such patients who may have added cardiovascular risk factors.
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Schweiger H, Ohlerth S, Gerber B. Contrast-enhanced ultrasound of both kidneys in healthy, non-anaesthetized cats. Acta Vet Scand 2015; 57:80. [PMID: 26608541 PMCID: PMC4660782 DOI: 10.1186/s13028-015-0172-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2015] [Accepted: 11/18/2015] [Indexed: 01/06/2023] Open
Abstract
Background Changes in perfusion are considered to play a key role in the pathophysiology of renal disease. Contrast-enhanced ultrasound (CEUS) has shown a promising diagnostic imaging technique to non-invasively and repetitively quantify tissue perfusion. Examination protocols have varied between studies regarding US equipment, quantification software, the use of sedation or anaesthesia, and animals. The purpose of the present study was, to assess the feasibility of a standardized CEUS protocol for perfusion analysis of both kidneys in nine healthy, non-anaesthetized cats. Results CEUS was fairly tolerable for all but one cat. In 6/18 kidneys (2 left, 4 right), a second contrast medium injection was needed due to motion artifacts. Perfusion variables such as peak intensity (PI), wash-in slope (WIS), wash-out slope (WOS) and mean transit time (MTT) did not significantly differ between left and right renal cortex and medulla nor between the cranial and caudal renal cortex within each kidney. In contrast, for all kidneys, mean PI, WIS, and MTT were significantly higher in the cortex than in the medulla (P = 0.001, 0.012 and <0.001, respectively). Conclusions The herein reported CEUS protocol and the perfusion measurements may serve as a baseline protocol and normal reference values for the evaluation of feline patients. However, the protocol and results may be of limited value in uncooperative animals.
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Bortolami E, Love EJ. Practical use of opioids in cats: a state-of-the-art, evidence-based review. J Feline Med Surg 2015; 17:283-311. [PMID: 25832586 PMCID: PMC11104155 DOI: 10.1177/1098612x15572970] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
RATIONALE Recent recognition of the need to improve pain management in cats has led to the investigation of the pharmacokinetics and efficacy of opioid analgesic drugs in this species. The results of these studies may be difficult to interpret because the effect of these drugs varies with dose, route of administration and the method used to assess them. As equipotency of different opioids is not known, it is hard to compare their effects. Animals do not verbalise the pain they feel and, in cats, it may be more difficult to recognise signs of pain in comparison with other species such as dogs. AIM This article reviews the use of opioid analgesics in cats. It must be remembered that not all drugs are licensed for use in cats, and that marketing authorisations vary between different countries.
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Affiliation(s)
- Elisa Bortolami
- Department of Animal Medicine, Production and Health, University of Padua, Italy
| | - Emma J Love
- School of Veterinary Sciences, University of Bristol, Langford, UK
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