Skip to main content
NCBI home page
Canadian Journal of Veterinary Research logoLink to Canadian Journal of Veterinary Research
. 1997 Apr;61(2):99–107.

Modification of cardiopulmonary and intestinal motility effects of xylazine with glycopyrrolate in horses.

S Singh 1, S S Young 1, W N McDonell 1, M O'Grady 1
PMCID: PMC1189385  PMID: 9114960

Abstract

Xylazine (XYL) administration in horses is accompanied by significant cardiovascular depression characterized by a 25-35% decrease in cardiac output (CO) which is likely to compromise tissue oxygen delivery (DO2), and usually vagally mediated bradycardia is an important cause of this reduced cardiovascular performance. To examine the possible benefit of preventing the bradycardiac response, 6 healthy horses were treated with intravenous (IV) saline (SAL) or 2.5 micrograms/kg glycopyrrolate (GLY) in a blinded, randomized, crossover trial. Fifteen minutes later, 1 mg/kg XYL was administered IV and systolic, diastolic and mean blood pressures (SBP, DBP, and MBP, respectively), central venous pressure (CVP), mean pulmonary artery pressure, heart rate (HR), CO, and arterial and mixed venous blood gases were measured at the following times: baseline, 2, 5, and 10 min post-SAL or GLY; and 2, 5, 10, 15, 30, 45 and 60 min post-XYL. Determination of cardiac index (CI), stroke index (SI), left ventricular work, systemic vascular resistance (SVR), DO2, oxygen uptake, and oxygen extraction ratio were made at the same time. Gastrointestinal (GI) motility was evaluated by four-quadrant auscultation for 24 h post-XYL. Statistical analysis of continuous variables was carried out using ANOVA for repeated measures and Wilcoxon's rank-sum test for non-parametric data. In GLY treated horses, HR, SBP, MBP, DBP, CI, DO2 and mixed venous oxygen tension were significantly higher up to 30 min after XYL (P < or = 0.02) while CVP and SI were significantly lower 2 and 5 min post-XYL, respectively. In both groups, GI motility as assessed by auscultation was virtually abolished for an hour, with a non-significant tendency for the decrease in motility to last longer in the GLY/XYL group. None of the treated horses developed abdominal discomfort. No significant difference was observed in the other variables. The study shows that 2.5 micrograms/kg GLY premedication reduces the cardiovascular depression caused by 1 mg/kg XYL, without adversely affecting GI motility.

Full text

PDF
99

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Adams S. B., Lamar C. H., Masty J. Motility of the distal portion of the jejunum and pelvic flexure in ponies: effects of six drugs. Am J Vet Res. 1984 Apr;45(4):795–799. [PubMed] [Google Scholar]
  2. Antonaccio M. J., Robson R. D., Kerwin L. Evidence for increased vagal tone and enhancement of baroreceptor reflex activity after xylazine (2-(2,6-dimethylphenylamino)-4-H-5,6-dihydro-1,3-thiazine) in anesthestized dogs. Eur J Pharmacol. 1973 Sep;23(3):311–316. doi: 10.1016/0014-2999(73)90102-7. [DOI] [PubMed] [Google Scholar]
  3. Benson G. J., Thurmon J. C. Intravenous anesthesia. Vet Clin North Am Equine Pract. 1990 Dec;6(3):513–528. doi: 10.1016/s0749-0739(17)30528-x. [DOI] [PubMed] [Google Scholar]
  4. Boyd C. J., McDonell W. N., Valliant A. Comparative hemodynamic effects of halothane and halothane-acepromazine at equipotent doses in dogs. Can J Vet Res. 1991 Apr;55(2):107–112. [PMC free article] [PubMed] [Google Scholar]
  5. Carter S. W., Robertson S. A., Steel C. J., Jourdenais D. A. Cardiopulmonary effects of xylazine sedation in the foal. Equine Vet J. 1990 Nov;22(6):384–388. doi: 10.1111/j.2042-3306.1990.tb04300.x. [DOI] [PubMed] [Google Scholar]
  6. Clark E. S., Thompson S. A., Becht J. L., Moore J. N. Effects of xylazine on cecal mechanical activity and cecal blood flow in healthy horses. Am J Vet Res. 1988 May;49(5):720–723. [PubMed] [Google Scholar]
  7. Clarke K. W., Hall L. W. "Xylazine"--a new sedative for horses and cattle. Vet Rec. 1969 Nov 8;85(19):512–517. doi: 10.1136/vr.85.19.512. [DOI] [PubMed] [Google Scholar]
  8. Donaldson L. L. Retrospective assessment of dobutamine therapy for hypotension in anesthetized horses. Vet Surg. 1988 Jan-Feb;17(1):53–57. doi: 10.1111/j.1532-950x.1988.tb00275.x. [DOI] [PubMed] [Google Scholar]
  9. Ducharme N. G., Fubini S. L. Gastrointestinal complications associated with the use of atropine in horses. J Am Vet Med Assoc. 1983 Feb 1;182(3):229–231. [PubMed] [Google Scholar]
  10. Dunkle N., Moise N. S., Scarlett-Kranz J., Short C. E. Cardiac performance in cats after administration of xylazine or xylazine and glycopyrrolate: echocardiographic evaluations. Am J Vet Res. 1986 Oct;47(10):2212–2216. [PubMed] [Google Scholar]
  11. England G. C., Clarke K. W., Goossens L. A comparison of the sedative effects of three alpha 2-adrenoceptor agonists (romifidine, detomidine and xylazine) in the horse. J Vet Pharmacol Ther. 1992 Jun;15(2):194–201. doi: 10.1111/j.1365-2885.1992.tb01007.x. [DOI] [PubMed] [Google Scholar]
  12. Evans D. L. Cardiovascular adaptations to exercise and training. Vet Clin North Am Equine Pract. 1985 Dec;1(3):513–531. doi: 10.1016/s0749-0739(17)30748-4. [DOI] [PubMed] [Google Scholar]
  13. Fosse R. T., Grong K., Stangeland L., Lekven J. Anesthetic interaction in cardiovascular research models: effects of xylazine and pentobarbital in cats. Am J Vet Res. 1987 Feb;48(2):211–218. [PubMed] [Google Scholar]
  14. Garner H. E., Amend J. F., Rosborough J. P. Effects on Bay Va 1470 on cardiovascular parameters in ponies. Vet Med Small Anim Clin. 1971 Oct;66(10):1016–passim. [PubMed] [Google Scholar]
  15. Gasthuys F., De Moor A., Parmentier D. Haemodynamic changes during sedation in ponies. Vet Res Commun. 1990;14(4):309–327. doi: 10.1007/BF00350713. [DOI] [PubMed] [Google Scholar]
  16. Gasthuys F., Muylle E., de Moor A., van Vlierberghe L., Nagels L. Influence of premedication and body position during halothane anaesthesia on intracardial pressures in the horse. Zentralbl Veterinarmed A. 1988 Dec;35(10):729–738. [PubMed] [Google Scholar]
  17. Gross M. E., Tranquilli W. J., Thurmon J. C., Benson G. J., Olson W. A. Hemodynamic effects of intravenous midazolam-xylazine-butorphanol in dogs. Vet Surg. 1990 Mar-Apr;19(2):173–180. doi: 10.1111/j.1532-950x.1990.tb01163.x. [DOI] [PubMed] [Google Scholar]
  18. Hinchcliff K. W., McKeever K. H., Muir W. W., 3rd Hemodynamic effects of atropine, dobutamine, nitroprusside, phenylephrine, and propranolol in conscious horses. J Vet Intern Med. 1991 Mar-Apr;5(2):80–86. doi: 10.1111/j.1939-1676.1991.tb00936.x. [DOI] [PubMed] [Google Scholar]
  19. Hubbell J. A., Bednarski R. M., Muir W. W. Xylazine and tiletamine-zolazepam anesthesia in horses. Am J Vet Res. 1989 May;50(5):737–742. [PubMed] [Google Scholar]
  20. Kerr D. D., Jones E. W., Huggins K., Edwards W. C. Sedative and other effects of xylazine given intravenously to horses. Am J Vet Res. 1972 Mar;33(3):525–532. [PubMed] [Google Scholar]
  21. Klide A. M., Calderwood H. W., Soma L. R. Cardiopulmonary effects of xylazine in dogs. Am J Vet Res. 1975 Jul;36(7):931–935. [PubMed] [Google Scholar]
  22. Kolata R. J., Rawlings C. A. Cardiopulmonary effects of intravenous xylazine, ketamine, and atropine in the dog. Am J Vet Res. 1982 Dec;43(12):2196–2198. [PubMed] [Google Scholar]
  23. Lavoie J. P., Pascoe J. R., Kurpershoek C. J. Effect of head and neck position on respiratory mechanics in horses sedated with xylazine. Am J Vet Res. 1992 Sep;53(9):1652–1657. [PubMed] [Google Scholar]
  24. Lavoie J. P., Pascoe J. R., Kurpershoek C. J. Effects of xylazine on ventilation in horses. Am J Vet Res. 1992 Jun;53(6):916–920. [PubMed] [Google Scholar]
  25. Lowe J. E., Sellers A. F., Brondum J. Equine pelvic flexure impaction. A model used to evaluate motor events and compare drug response. Cornell Vet. 1980 Oct;70(4):401–412. [PubMed] [Google Scholar]
  26. Maze M., Tranquilli W. Alpha-2 adrenoceptor agonists: defining the role in clinical anesthesia. Anesthesiology. 1991 Mar;74(3):581–605. [PubMed] [Google Scholar]
  27. Mirakhur R. K., Dundee J. W. Glycopyrrolate: pharmacology and clinical use. Anaesthesia. 1983 Dec;38(12):1195–1204. doi: 10.1111/j.1365-2044.1983.tb12525.x. [DOI] [PubMed] [Google Scholar]
  28. Muir W. W. Effects of atropine on cardiac rate and rhythm in dogs. J Am Vet Med Assoc. 1978 Apr 15;172(8):917–921. [PubMed] [Google Scholar]
  29. Muir W. W., Piper F. S. Effect of xylazine on indices of myocardial contractility in the dog. Am J Vet Res. 1977 Jul;38(7):931–934. [PubMed] [Google Scholar]
  30. Muir W. W., Skarda R. T., Milne D. W. Estimation of cardiac output in the horse by thermodilution techniques. Am J Vet Res. 1976 Jun;37(6):697–700. [PubMed] [Google Scholar]
  31. Muir W. W., Skarda R. T., Sheehan W. Hemodynamic and respiratory effects of a xylazine-acetylpromazine drug combination in horses. Am J Vet Res. 1979 Nov;40(11):1518–1522. [PubMed] [Google Scholar]
  32. Parks C., Manohar M., Lundeen G. Regional myocardial blood flow and coronary vascular reserve in unanesthetized ponies during pacing-induced ventricular tachycardia. J Surg Res. 1983 Aug;35(2):119–131. doi: 10.1016/0022-4804(83)90134-8. [DOI] [PubMed] [Google Scholar]
  33. Roberts M. C., Argenzio A. Effects of amitraz, several opiate derivatives and anticholinergic agents on intestinal transit in ponies. Equine Vet J. 1986 Jul;18(4):256–260. doi: 10.1111/j.2042-3306.1986.tb03620.x. [DOI] [PubMed] [Google Scholar]
  34. Roger T., Ruckebusch Y. Colonic alpha 2-adrenoceptor-mediated responses in the pony. J Vet Pharmacol Ther. 1987 Dec;10(4):310–318. doi: 10.1111/j.1365-2885.1987.tb00107.x. [DOI] [PubMed] [Google Scholar]
  35. Rutkowski J. A., Eades S. C., Moore J. N. Effects of xylazine butorphanol on cecal arterial blood flow, cecal mechanical activity, and systemic hemodynamics in horses. Am J Vet Res. 1991 Jul;52(7):1153–1158. [PubMed] [Google Scholar]
  36. Rutkowski J. A., Ross M. W., Cullen K. Effects of xylazine and/or butorphanol or neostigmine on myoelectric activity of the cecum and right ventral colon in female ponies. Am J Vet Res. 1989 Jul;50(7):1096–1101. [PubMed] [Google Scholar]
  37. Schmitt H., Fournadjiev G., Schmitt H. Central and peripheral effects of 2-(2,6-dimethylphenylamino)-4-H-5,6-dihydro-1,3-thiazin (Bayer 1470) on the sympathetic system. Eur J Pharmacol. 1970 May;10(2):230–238. doi: 10.1016/0014-2999(70)90277-3. [DOI] [PubMed] [Google Scholar]
  38. Wagner A. E., Muir W. W., 3rd, Hinchcliff K. W. Cardiovascular effects of xylazine and detomidine in horses. Am J Vet Res. 1991 May;52(5):651–657. [PubMed] [Google Scholar]

Articles from Canadian Journal of Veterinary Research are provided here courtesy of Canadian Veterinary Medical Association

RESOURCES