Sympathetic stimulating effects of sufentanil in the cat are mediated centrally

Comparison of perioperative racemic methadone, levo‐methadone and dextromoramide in cats using indicators of post‐operative pain

“…l ‐Polamivet contains fenpipramide, which causes pupillary dilatation by relaxing the sphincter muscle of the iris (Amman 1952). Mydriasis in conjunction with excitation, as described by Gaumann et al. (1988), was only seen in one cat after surgery.…”

“…In the current study, changes in RR were not noted 20 minutes after the administration of any opioid, and this supports the findings of Dobromylskyj (1993) for methadone. Mydriasis is a well‐recognised effect of opioids in cats (Gaumann et al. 1988), although the mechanisms are unknown.…”

Determination of the sevoflurane sparing effect of methadone in cats

“…2004; Lamont & Mathews 2007; Ferreira et al. 2009), most likely because of the central stimulatory effect and an increase in sympathetic outflow caused by this class of drugs in this species (Gaumann et al. 1988; Pascoe et al.…”

“…1993). In cats, administration of opioids has been associated with stimulation of the sympathetic nervous system (Gaumann et al. 1988; Pascoe et al.…”

Comparison of perioperative analgesic efficacy between methadone and butorphanol in cats

“…23 Although the present study did not evaluate MAC, the amount of isoflurane required to maintain anesthesia in both groups (1.0 ± 0.3% and 0.9 ± 0.2% for the methadone and butorphanol groups, respectively) was less than the MAC. [25][26][27][28][29] The present study used a partially validated multidimensional composite scale for assessing postoperative pain in cats undergoing ovariohysterectomy. [2][3][4]13,15,24 In cats, the degree of MAC reduction that occurs with the perioperative use of opioids is a balance between the antinociceptive qualities of opioids, which promote MAC reduction, and the excitatory characteristics of opioids, which oppose MAC reduction and sedation.…”