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Maxwell H. Gluck Equine Research Center Faculty Publications

2000

Articles 1 - 2 of 2

Full-Text Articles in Large or Food Animal and Equine Medicine

Effect Of Amitraz And Xylazine On Some Physiological Variables Of Horses, A. Queiroz-Neto, A. B. Carregaro, G. Zamur, J Daniel Harkins, Thomas Tobin, M. I. Mataqueiro, S. C. Gonçalves Jan 2000

Effect Of Amitraz And Xylazine On Some Physiological Variables Of Horses, A. Queiroz-Neto, A. B. Carregaro, G. Zamur, J Daniel Harkins, Thomas Tobin, M. I. Mataqueiro, S. C. Gonçalves

Maxwell H. Gluck Equine Research Center Faculty Publications

The effect of the intravenous injection of amitraz (0.1 mg/kg) to horses on cardiac activity, respiratory rate, intestinal motor activity, rectal temperature, sweating and masticating was evaluated and compared to the effect of intravenous administration of xylazine (1mg/kg, iv) on heart rate, respiratory rate and intestinal activity. Amitraz caused a significant decrease in heart activity, respiratory rate and intestinal movements, but these effects were not as pronounced as those caused by xylazine. Amitraz also caused a significant relaxation of the rectal smooth muscle, and an apparent increase in sweating and in the frequency of horses found masticating hay. Rectal temperature …


Remifentanil In The Horse: Identification And Detection Of Its Major Urinary Metabolite, A. F. Lehner, P. Almeida, J. Jacobs, J Daniel Harkins, W. Karpiesiuk, W. E. Woods, L. Dirikolu, Jeffrey M Bosken, W. G. Carter, J. Boyles, C. Holtz, T. Heller, C. Nattrass, M. Fisher, Thomas Tobin Jan 2000

Remifentanil In The Horse: Identification And Detection Of Its Major Urinary Metabolite, A. F. Lehner, P. Almeida, J. Jacobs, J Daniel Harkins, W. Karpiesiuk, W. E. Woods, L. Dirikolu, Jeffrey M Bosken, W. G. Carter, J. Boyles, C. Holtz, T. Heller, C. Nattrass, M. Fisher, Thomas Tobin

Maxwell H. Gluck Equine Research Center Faculty Publications

Remifentanil (4-methoxycarbonyl-4-[(1-oxopropyl)phyenylamino]-1- piperidinepropionic acid methyl ester) is a μ-opioid receptor agonist with considerable abuse potential in racing horses. The identification of its major equine urinary metabolite, 4-methoxycarbonyl-4-[(1- oxopropyl)phenylamino]-1-piperidinepropionic acid, an ester hydrolysis product of remifentanil is reported. Administration of remifentanil HCl (5 mg, intravenous) produced clear-cut locomotor responses, establishing the clinical efficacy of this dose. ELISA analysis of postadministration urine samples readily detected fentanyl equivalents in these samples. Mass spectrometric analysis, using solid-phase extraction and trimethylsilyl (TMS) derivatization, showed the urine samples contained parent remifentanil in low concentrations, peaking at 1 h. More significantly, a major peak was identified as …