{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,9]],"date-time":"2026-04-09T13:49:11Z","timestamp":1775742551142,"version":"3.50.1"},"reference-count":35,"publisher":"American Veterinary Medical Association (AVMA)","issue":"12","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["javma"],"published-print":{"date-parts":[[2008,6,15]]},"abstract":"<jats:title>Abstract<\/jats:title>\n<jats:p><jats:bold>Objective<\/jats:bold>\u2014To compare the effect of oral administration of tramadol alone and with IV administration of butorphanol or hydromorphone on the minimum alveolar concentration (MAC) of sevoflurane in cats.<\/jats:p>\n<jats:p><jats:bold>Design<\/jats:bold>\u2014Crossover study.<\/jats:p>\n<jats:p><jats:bold>Animals<\/jats:bold>\u20148 healthy 3-year-old cats.<\/jats:p>\n<jats:p><jats:bold>Procedures<\/jats:bold>\u2014Cats were anesthetized with sevoflurane in 100% oxygen. A standard tail clamp method was used to determine the MAC of sevoflurane following administration of tramadol (8.6 to 11.6 mg\/kg [3.6 to 5.3 mg\/lb], PO, 5 minutes before induction of anesthesia), butorphanol (0.4 mg\/kg [0.18 mg\/lb], IV, 30 minutes after induction), hydromorphone (0.1 mg\/kg [0.04 mg\/lb], IV, 30 minutes after induction), saline (0.9% NaCl) solution (0.05 mL\/kg [0.023 mL\/lb], IV, 30 minutes after induction), or tramadol with butorphanol or with hydromorphone (same doses and routes of administration). Naloxone (0.02 mg\/kg [0.009 mg\/lb], IV) was used to reverse the effects of treatments, and MACs were redetermined.<\/jats:p>\n<jats:p><jats:bold>Results<\/jats:bold>\u2014Mean \u00b1 SEM MACs for sevoflurane after administration of tramadol (1.48 \u00b1 0.20%), butorphanol (1.20 \u00b1 0.16%), hydromorphone (1.76 \u00b1 0.15%), tramadol and butorphanol (1.48 \u00b1 0.20%), and tramadol and hydromorphone (1.85 \u00b1 0.20%) were significantly less than those after administration of saline solution (2.45 \u00b1 0.22%). Naloxone reversed the reductions in MACs.<\/jats:p>\n<jats:p><jats:bold>Conclusions and Clinical Relevance<\/jats:bold>\u2014Administration of tramadol, butorphanol, or hydromorphone reduced the MAC of sevoflurane in cats, compared with that in cats treated with saline solution. The reductions detected were likely mediated by effects of the drugs on opioid receptors. An additional reduction in MAC was not detected when tramadol was administered with butorphanol or hydromorphone.<\/jats:p>","DOI":"10.2460\/javma.232.12.1834","type":"journal-article","created":{"date-parts":[[2008,6,16]],"date-time":"2008-06-16T13:31:06Z","timestamp":1213623066000},"page":"1834-1840","source":"Crossref","is-referenced-by-count":30,"title":["Effect of orally administered tramadol alone or with an intravenously administered opioid on minimum alveolar concentration of sevoflurane in cats"],"prefix":"10.2460","volume":"232","author":[{"given":"Jeff C. H.","family":"Ko","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lisa A.","family":"Abbo","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ann B.","family":"Weil","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Brenda M.","family":"Johnson","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tomohito","family":"Inoue","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mark E.","family":"Payton","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1272","reference":[{"key":"ref1","series-title":"Vet Anaesth Analg","first-page":"132","article-title":"Dose-related thermal antinociceptive effects of intravenous hydromorphone in cats","volume":"34","author":"Wegner","year":"2007"},{"key":"ref2","series-title":"J Vet Pharmacol Ther","first-page":"531","article-title":"Effects of subcutaneous methadone, morphine, buprenorphine or saline on thermal and pressure thresholds in cats","volume":"29","author":"Steagall","year":"2006"},{"key":"ref3","series-title":"Vet Anaesth Analg","first-page":"344","article-title":"Effects of buprenorphine, carprofen and saline on thermal mechanical nociceptive threshold in cats","volume":"34","author":"Steagall","year":"2007"},{"key":"ref4","series-title":"J Am Vet Med Assoc","first-page":"1013","article-title":"Evaluation of transdermal fentanyl patches for analgesia in cats undergoing onchyectomy","volume":"217","author":"Franks","year":"2000"},{"key":"ref5","series-title":"Am J Vet Res","first-page":"699","article-title":"Antinociceptive effects of butorphanol, buprenorphine, or both, administered intramuscularly in cats","volume":"68","author":"Johnson","year":"2007"},{"key":"ref6","series-title":"Vet Anaesth Analg","first-page":"29","article-title":"A preliminary investigation comparing pre-operative morphine and buprenorphine for postoperative analgesia and sedation in cats","volume":"29","author":"Stanway","year":"2002"},{"key":"ref7","series-title":"Vet Rec","first-page":"462","article-title":"Changes in thermal threshold response in eight cats after administration of buprenorphine, butorphanol and morphine","volume":"153","author":"Robertson","year":"2003"},{"key":"ref8","series-title":"J Am Vet Med Assoc","first-page":"65","article-title":"Evaluation of signs of postoperative pain and complications after forelimb onychectomy in cats receiving buprenorphine alone or with bupivicaine administered as a four-point regional nerve block","volume":"228","author":"Curcio","year":"2006"},{"key":"ref9","series-title":"J Vet Intern Med","first-page":"190","article-title":"Antinociceptive effects of hydromorphone, butorphanol, or the combination in cats","volume":"18","author":"Lascelles","year":"2004"},{"key":"ref10","series-title":"Am J Vet Res","first-page":"1274","article-title":"Effect of alfentanil on the minimum alveolar concentration of isoflurane in cats","volume":"58","author":"Ilkiw","year":"1997"},{"key":"ref11","series-title":"Am J Vet Res","first-page":"1198","article-title":"Effects of morphine, butorphanol, buprenorphine, and U50488H on the minimum alveolar concentration of isoflurane in cats","volume":"63","author":"Ilkiw","year":"2002"},{"key":"ref12","series-title":"Vet Anaesth Analg","first-page":"183","article-title":"Effect of transdermally administered fentanyl on the minimum alveolar concentration of isoflurane in cats","volume":"31","author":"Yackey","year":"2004"},{"key":"ref13","series-title":"Am J Vet Res","first-page":"1267","article-title":"Cardiovascular effects of equipotent isoflurane and alfentanil\/isoflurane minimum alveolar concentration multiple in cats","volume":"58","author":"Pascoe","year":"1997"},{"key":"ref14","series-title":"Am J Vet Res","first-page":"1471","article-title":"Effects of epidural administration of morphine and buprenorphine on the minimum alveolar concentration of isoflurane in cats","volume":"67","author":"Pypendop","year":"2006"},{"key":"ref15","series-title":"Am J Vet Res","first-page":"20","article-title":"Hemodynamic effects of sevoflurane in cats","volume":"65","author":"Pypendop","year":"2004"},{"key":"ref16","series-title":"Res Vet Sci","first-page":"205","article-title":"Cardiopulmonary effects of sevoflurane in cats: comparison with isoflurane, halothane, and enflurane","volume":"63","author":"Hikasa","year":"1997"},{"key":"ref17","series-title":"Br J Clin Pharmacol","first-page":"338","article-title":"Tramadol hydrochloride\u2014not just another opioid agonist","volume":"39","author":"Eggers","year":"1995"},{"key":"ref18","series-title":"Clin Pharmacokinet","first-page":"879","article-title":"Clinical pharmacology of tramadol","volume":"43","author":"Grond","year":"2004"},{"key":"ref19","series-title":"Pain","first-page":"234","article-title":"Tramadol, fentanyl and sufentanil but not morphine block voltage-operated sodium channels","volume":"126","author":"Haeseler","year":"2006"},{"key":"ref20","series-title":"Vet Anaesth Analg","first-page":"220","article-title":"A comparison of preoperative tramadol and morphine for the control of early postoperative pain in canine ovariohysterectomy","volume":"30","author":"Mastrocinque","year":"2003"},{"key":"ref21","series-title":"J Feline Med Surg","first-page":"24","article-title":"Antinociceptive effects of tramadol and acepromazine in cats","volume":"10","author":"Steagall","year":"2008"},{"key":"ref22","series-title":"Anesthesiology","first-page":"420","article-title":"Respiratory depression by tramadol in the cat: involvement of opioid receptors","volume":"98","author":"Teppema","year":"2003"},{"key":"ref23","series-title":"J Anesth","first-page":"113","article-title":"The minimum alveolar concentration of sevoflurane in cats","volume":"2","author":"Doi","year":"1988"},{"key":"ref24","series-title":"J Am Vet Med Assoc","first-page":"1025","article-title":"Effects of butorphanol and carprofen on the minimal alveolar concentration of isoflurane in dogs","volume":"217","author":"Ko","year":"2000"},{"key":"ref25","series-title":"J Vet Pharmacol Ther","first-page":"239","article-title":"Pharmacokinetics of tramadol and the metabolite O-desmethyltramadol in dogs","volume":"27","author":"Kukanich","year":"2004"},{"key":"ref26","series-title":"Am J Vet Res","first-page":"93","article-title":"Relationship of bispectral index to minimum alveolar concentration multiples of sevoflurane in cats","volume":"65","author":"Lamont","year":"2004"},{"key":"ref27","series-title":"Br J Anaesth","first-page":"275","article-title":"Animal dependence of inhaled anaesthetic requirements in cats","volume":"92","author":"Barter","year":"2004"},{"key":"ref28","series-title":"J Pharmacol Exp Ther","first-page":"275","article-title":"Opioid and nonopioid components independently contribute to the mechanism of action of tramadol, an \u2018atypical\u2019 opioid analgesic","volume":"260","author":"Raffa","year":"1992"},{"key":"ref29","series-title":"Br J Anaesth","first-page":"780","article-title":"Effects of tramadol on minimum alveolar concentration (MAC) of isoflurane in rats","volume":"83","author":"Wolff","year":"1999"},{"key":"ref30","series-title":"Anesth Analg","first-page":"1713","article-title":"The addition of a tramadol infusion to morphine patient-controlled analgesia after abdominal surgery: a double-blinded, placebo-controlled randomized trial","volume":"95","author":"Webb","year":"2002"},{"key":"ref31","series-title":"Anaesthesist","first-page":"11","article-title":"The significance of tramadol as an intraoperative analgesic. A randomised double-blind study in comparison with placebo [in German]","volume":"34","author":"Lehmann","year":"1985"},{"key":"ref32","series-title":"Br J Anaesth","first-page":"247","article-title":"Tramadol","volume":"74","author":"Eggers","year":"1995"},{"key":"ref33","series-title":"Br J Anaesth","first-page":"415","article-title":"JC. Effect of tramadol on depth of anaesthesia","volume":"76","author":"Coetzee","year":"1996"},{"key":"ref34","series-title":"Br J Anaesth","first-page":"705","article-title":"Effect of tramadol on electroencephalographic and auditory-evoked response variables during light anaesthesia","volume":"85","author":"Vaughan","year":"2000"},{"key":"ref35","series-title":"Anaesthesist","first-page":"20","article-title":"Tramadol infusion anesthesia with the substitution of enflurane and various nitrous oxide concentrations [in German]","volume":"34","author":"Paravicini","year":"1985"}],"container-title":["Journal of the American Veterinary Medical Association"],"original-title":[],"link":[{"URL":"https:\/\/avmajournals.avma.org\/view\/journals\/javma\/232\/12\/javma.232.12.1834.xml","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/avmajournals.avma.org\/downloadpdf\/journals\/javma\/232\/12\/javma.232.12.1834.xml","content-type":"text\/html","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/avmajournals.avma.org\/downloadpdf\/journals\/javma\/232\/12\/javma.232.12.1834.xml","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,3,7]],"date-time":"2025-03-07T13:27:30Z","timestamp":1741354050000},"score":1,"resource":{"primary":{"URL":"https:\/\/avmajournals.avma.org\/view\/journals\/javma\/232\/12\/javma.232.12.1834.xml"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2008,6,15]]},"references-count":35,"journal-issue":{"issue":"12"},"URL":"https:\/\/doi.org\/10.2460\/javma.232.12.1834","relation":{},"ISSN":["0003-1488"],"issn-type":[{"value":"0003-1488","type":"print"}],"subject":[],"published":{"date-parts":[[2008,6,15]]}}}