Pain
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A water-soluble three-layered oral mucosa-adhesive film made from hydroxypropyl cellulose containing dibucaine (0.25 mg of drug/cm(2)) was designed for alleviation of severe pain due to oral ulcers, caused by chemotherapy and/or radiotherapy. We report two patients with constant severe pain ulcers treated with the dibucaine film. Patients were asked to record the time that pain was relieved while chewing following first application of the film. Pain relief lasted for 2-5 h after application of the dibucaine film.
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In this preliminary study, we evaluated the effects of methylnaltrexone, a peripheral opioid-receptor antagonist, on chronic opioid-induced gut motility and transit changes in four subjects with chronic methadone-induced constipation. Subjects participated in this single blind, placebo controlled study for up to 8 days. We gave placebo the first day; for the remainder of the study, we gave intravenous methylnaltrexone (0.05-0.45 mg/kg) twice daily. ⋯ Oral-cecal transit times of Subjects 1, 3, and 4 were reduced from 150, 150 and 150 min (after placebo) to 90, 60 and 60 min (with methylnaltrexone), respectively. Our preliminary results demonstrate that low dose intravenous methylnaltrexone effectively reversed chronic methadone-induced constipation and delay in gut transit time. Thus, we anticipate that cancer patients receiving chronic opioids may also have increased sensitivity to methylnaltrexone, and that low dose methylnaltrexone may have clinical utility in managing opioid-induced constipation in chronic-pain patients.
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In this study, pain perception, somatosensory event-related potential (SERP) and skin conductance response (SCR) changes during hypnotic suggestions of Deep Relaxation, Dissociated Imagery, Focused Analgesia, and Placebo, compared with a Waking baseline condition, were investigated. SERPs were recorded from frontal, temporal, central, and parietal scalp sites. Ten high, 9 mid, and 10 low hypnotizable right-handed women participated in the experiment. ⋯ These subjects also showed faster habituation of SCRs when compared with mid and low hypnotizables. During Dissociated Imagery and Focused Analgesia, highly hypnotizable subjects also disclosed a smaller total number of evoked SCRs than did mid and low hypnotizable subjects. The results are discussed considering possible common and different mechanisms to account for the effects of different hypnotic suggestions.
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Pain intensity ratings of 'usual' pain, or pain 'on average', are gaining in popularity since they are arguably a more realistic measure of a patient's pain status than the single snapshot of 'current' pain. An alternative to the 'actual average' of ratings obtained from multiple measures is the single rating of patients' recall of their 'usual' pain over a period of time, usually 1 week. The use of such a scale relies on the assumption that patients can accurately recall their 'usual' pain. ⋯ Using the Intra-class Correlation Coefficient (ICC) to compute accuracy, the single rating asking patients to estimate their pain 'on average' over the week was found to be an accurate measure of 'actual average' pain intensity (ICC=0.82) and more accurate than 'current' pain (ICC=0.66). Although some composite measures of single ratings gave more accurate estimates of 'actual average' pain, this was not considered sufficient advantage to advocate their use. The results of this study propose the single rating of pain 'on average' as a valid and practical measure of a patient's pain intensity over a period of 1 week.
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The development of tolerance following repeated doses of morphine hinders the treatment of clinical pain. We have previously shown that morphine tolerance develops in neuropathic rats without cross-tolerance to a systemic kappa-opioid agonist; in the current work, using paw-pressure vocalization thresholds, we studied the antinociceptive effect of the peripherally-selective kappa (kappa)-opioid agonist, asimadoline, in both morphine-tolerant and opioid-naïve rats 2 weeks after sciatic nerve injury. In naïve rats, intraplantar (i.pl.) injection of asimadoline into the nerve-injured paw, at doses of 10, 15 and 20 (but not 30) microg, dose-dependently relieved the mechanical allodynia-like behaviour. ⋯ These results confirm that at low doses, asimadoline exerts its action only in the periphery. In morphine-tolerant rats (after 10 mg/kg s.c. , twice daily for 4 days) and naïve, saline-pretreated rats, asimadoline (15 microg, i.pl.) relieved the mechanical allodynia-like behaviour to the same extent, indicating no cross-tolerance between morphine and the peripherally-selective drug. Our findings show promise for the treatment of neuropathic pain with low doses of peripherally-selective kappa-opioids.