Pain
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This case report describes the successful alleviation of the pain of pancreatic carcinoma with intravenous phentolamine mesylate. A 2 day infusion gave relief for 26 days on the first occasion and for 12 weeks after the second infusion. The possible mode of action is discussed.
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Our previous studies in the Sprague-Dawley rat showed that the intrinsic antinociceptive effects of oxycodone are naloxone reversible in a manner analogous to morphine but that in contrast to morphine, oxycodone's antinociceptive effects have a rapid onset of maximum effect (approximately 5-7 min compared to 30-45 min for morphine), comprise one antinociceptive phase (compared to two phases) and are of relatively short duration (approximately 90 min compared to approximately 180 min). In the present study, administration of a range of selective opioid receptor antagonists has shown that the intrinsic antinociceptive effects of oxycodone (171 nmol) are not attenuated by i.c.v. administration of (i) naloxonazine, a mu1-selective opioid receptor antagonist, or (ii) naltrindole, a delta-selective opioid receptor antagonist, in doses that completely attenuated the intrinsic antinociceptive effects of equipotent doses of the respective mu- and delta-opioid agonists, morphine and enkephalin-[D-Pen(2,5)] (DPDPE). ⋯ Importantly, the antinociceptive effects of oxycodone (171 nmol i.c.v.) were markedly attenuated by the prior i.c.v. administration of the selective kappa-opioid receptor antagonist, norbinaltorphimine (nor-BNI), in a dose (0.3 nmol) that did not attenuate the antinociceptive effects of an equipotent dose of i.c.v. morphine (78 nmol). Taken together, these data strongly suggest that the intrinsic antinociceptive effects of oxycodone are mediated by kappa-opioid receptors, in contrast to morphine which interacts primarily with mu-opioid receptors.
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In recent years, multidisciplinary pain programs were seen to successfully treat patients by basing treatment on a combination of physical exercise and psychological interventions. However, in spite of their effectiveness, it still remains to be clarified exactly which features of these programs were responsible for patient improvement. Cognitive-behavioral models posit that improvement is due, in part, to changes in patient coping strategies. ⋯ Other objective parameters, such as medical history, physical impairment and general physical variables were seen to have little predictive value in determining a return to work. The results suggest that the primary target point for further investigation is the analysis of the patients' beliefs about their pain. Our results indicate that future research must be attentive to the complex interactions between environmental factors and the coping demands posed by the specific nature of pain problems.
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Previous studies of intrathecal ketamine use in humans have documented the clinical effects of its administration without reference to local central nervous system (CNS) toxicity (Reich and Silvay, 1989). Although several post-mortem studies in small groups of rabbits, monkeys, and baboons have largely shown no significant CNS damage after intrathecal ketamine use, a study in rats reported vacuolation of dorsal root ganglia (Ahuja, 1983). We report post-mortem CNS histopathological changes of subpial spinal cord vacuolation in a terminally ill cancer patient who received continuous infusion intrathecal ketamine at a rate of 5 mg/day for a duration of 3 weeks.
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Randomized Controlled Trial Multicenter Study Clinical Trial
Controlled-release oxycodone and morphine in cancer related pain.
Controlled-release (CR) formulations of oxycodone and morphine were compared in 45 patients with chronic cancer pain. The study was started with an open-label, randomised titration phase to achieve stable pain control for at least 48 h, followed by a double-blind, randomised, crossover phase in two periods, 3-6 days each. To blind the study using available tablet strengths, the dose ratio of oxycodone to morphine was set at 2:3. ⋯ If the results of the two periods were combined, the patients consumed significantly more escape doses and the mean pain intensities were significantly greater with CR oxycodone. The total opioid consumption ratio of oxycodone to morphine was 2:3 when oxycodone was administered first, and 3:4 when oxycodone was administered after morphine. The total incidence of adverse experiences reported by the patients was similar, but significantly more vomiting occurred with morphine, whereas constipation was more common with oxycodone.