Effects of tramadol or morphine in dogs undergoing castration on intra-operative electroencephalogram responses and post-operative pain

Kongara, Kavitha; Chambers, J.P.; Johnson, Craig B.; Dukkipati, V.S.R.

doi:10.1080/00480169.2013.780280

Cited by 15 publications

(12 citation statements)

References 21 publications

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“…In a study conducted on dogs, Ptot decreased significantly after electric stimulation followed by administration of morphine (Kongara et al 2010). On the contrary, Ptot did not decrease from baseline in response to castration after administration of morphine (Kongara et al 2013); whereas, tramadol was unable to prevent decrease in Ptot at the time of testicle removal in the same study. This discrepancy in the results reported and results of this study may likely be due to the difference in the experimental conditions or intensity of noxious stimulations used.…”

Section: Discussionmentioning

confidence: 77%

“…Therefore, changes in EEG variables of nociception in anaesthetised animals and pain in conscious animals have received much attention (Kongara et al 2010, Kongara et al 2014, Zulkifli et al 2014. Most commonly reported EEG variables in animals are median frequency, spectral edge frequency 95% and total power (Haga and Dolvik 2005, Gibson et al 2007, Murrell et al 2007, Kongara et al 2013). Median frequency is "the frequency below which 50% of the total power of the EEG is located".…”

Section: Introductionmentioning

confidence: 99%

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Electroencephalographic changes associated with non-invasive nociceptive stimulus in minimally anaesthetised dogs

Kaka¹,

Goh²,

Chean³

et al. 2016

Polish Journal of Veterinary Sciences

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Electroencephalography (EEG) has been reported as an objective, non-invasive and stress free technique for nociceptive studies. Electrical stimuli can be used to evaluate the efficacy of centrally acting agents. Peripheral nerve stimulator can be a good and cheap source of electric stimulus for studies of nociception, and studies evaluating analgesic effect of drugs under EEG. In this study suitability of peripheral nerve stimulator, and milliamperage for nociceptive studies under electroencephalography were evaluated. Six dogs were subjected to electric stimulus of 20, 40, 60 and 80 milliamperes (mAs) before and after tramadol administration at 4 mg/kg IV. Electroencephalograph was recorded during electric stimulus prior tramadol (pre-tramadol) and during electric stimulus after tramadol (post-tramadol) under minimal anaesthesia. Anaesthesia was induced with propofol and maintained with halothane at a stable concentration between 0.85 and 0.95%. Pre-tramadol median frequency (MF) increased significantly (p<0.05) at 40, 60 and 80 mAs post-electric stimulus compared to baseline MF. No difference in pre-tramadol MF was observed between 60 and 80 mAs. Tramadol produced significant effect by depression of MF at all intensities. The effect was less evident at 80 mAs. The results revealed that tramadol produced evident effect between 20 and 60 mAs. Thus, it is concluded that nerve stimulator can be used with the current between 20 and 60 mAs for nociceptive studies.

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Section: Discussionmentioning

confidence: 77%

Section: Introductionmentioning

confidence: 99%

Electroencephalographic changes associated with non-invasive nociceptive stimulus in minimally anaesthetised dogs

Kaka¹,

Goh²,

Chean³

et al. 2016

Polish Journal of Veterinary Sciences

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“…However, this use in dogs is controversial, since clinical efficacy studies have produced conflicting results. Some studies indicate that tramadol is equally or more effective than other drugs used to treat pain in dogs (Mastrocinque and Fantoni, 2003;Almeida et al, 2010;Martins et al, 2010;Clark et al, 2011;KuKanich and Papich, 2011;Malek et al, 2012;Neves et al, 2012;Rialland et al, 2012;Kongara et al, 2013;Morgaz et al, 2013;Teixeira et al, 2013;Cardozo et al, 2014), whereas other studies have shown relatively poor analgesic efficacy in dogs (Davila et al, 2013;Delgado et al, 2014;Kögel et al, 2014). Tramadol is considered a prodrug with regard to opioid analgesic effects, requiring metabolic activation by cytochrome P450 (P450) enzymes.…”

Section: Introductionmentioning

confidence: 99%

Tramadol Metabolism toO-Desmethyl Tramadol (M1) andN-Desmethyl Tramadol (M2) by Dog Liver Microsomes: Species Comparison and Identification of Responsible Canine Cytochrome P450s

et al. 2016

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Tramadol is widely used to manage mild to moderately painful conditions in dogs. However, this use is controversial since clinical efficacy studies in dogs showed conflicting results, while pharmacokinetic studies demonstrated relatively low circulating concentrations of O-desmethyltramadol (M1). Analgesia has been attributed to the opioid effects of M1, while tramadol and the other major metabolite (N-desmethyltramadol, M2) are considered inactive at opioid receptors. The aims of this study were to determine whether cytochrome P450 (CYP) dependent M1 formation by dog liver microsomes is slower compared with cat and human liver microsomes; and identify the CYPs responsible for M1 and M2 formation in canine liver. Since tramadol is used as a racemic mixture of (+)- and (-)-stereoisomers, both (+)-tramadol and (-)- tramadol were evaluated as substrates. M1 formation from tramadol by liver microsomes from dogs was slower than from cats (3.9-fold), but faster than humans (7-fold). However, M2 formation by liver microsomes from dogs was faster than from cats (4.8-fold) and humans (19-fold). Recombinant canine CYP activities indicated that M1 was formed by CYP2D15, while M2 was largely formed by CYP2B11 and CYP3A12. This was confirmed by dog liver microsomes studies that showed selective inhibition of M1 formation by quinidine and M2 formation by chloramphenicol and CYP2B11 antiserum, and induction of M2 formation by phenobarbital. Findings were similar for both (+)-tramadol and (-)-tramadol. In conclusion, low circulating M1 concentrations in dogs is explained in part by low M1 formation and high M2 formation, which are mediated by CYP2D15 and CYP2B11/CYP3A12, respectively.

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“…other minimal anaesthesia studies(Murrell et al 2010;Kongara et al 2013). These results reflect 335 the difficulty of maintaining normocapnia in cattle and are not unusually high for large ruminants 336(Klein & Fisher 1988).…”

mentioning

confidence: 99%

Mitigation of electroencephalographic and cardiovascular responses to castration in Bos indicus bulls following the administration of either lidocaine or meloxicam

Lehmann

Musk

Laurence

et al. 2017

Veterinary Anaesthesia and Analgesia

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Effects of tramadol or morphine in dogs undergoing castration on intra-operative electroencephalogram responses and post-operative pain

Abstract: Tramadol and morphine administered pre-operatively provided a similar degree of post-operative analgesia in male dogs at the doses tested.

Cited by 15 publications

References 21 publications

Electroencephalographic changes associated with non-invasive nociceptive stimulus in minimally anaesthetised dogs

Electroencephalographic changes associated with non-invasive nociceptive stimulus in minimally anaesthetised dogs

Tramadol Metabolism toO-Desmethyl Tramadol (M1) andN-Desmethyl Tramadol (M2) by Dog Liver Microsomes: Species Comparison and Identification of Responsible Canine Cytochrome P450s

Mitigation of electroencephalographic and cardiovascular responses to castration in Bos indicus bulls following the administration of either lidocaine or meloxicam

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