Pain
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Multicenter Study Clinical Trial
Direct conversion from oral morphine to transdermal fentanyl: a multicenter study in patients with cancer pain.
Direct conversion from oral morphine to transdermal fentanyl with a ratio of oral morphine/transdermal fentanyl (100:1 mg) daily was examined in patients with cancer pain. Patients with a 'stable and low level of cancer pain' receiving a constant dosage of sustained release morphine during a pre-study phase of 6 days were included in the study. Initial fentanyl dosage was calculated by a conversion table. ⋯ Cutaneous reactions to the patch were rare, mild and transient. Patients and physicians reported satisfaction with the transdermal therapy. 94.7% of the patients chose to continue the transdermal fentanyl therapy at the end of the study due to better performance in comparison to oral morphine. Due to these results an initial conversion from oral morphine to transdermal fentanyl with the ratio of 100:1 is safe and effective.
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Central pain syndromes (CPS) could be caused by disinhibition of spinothalamic excitability or by other central nervous system (CNS) changes caused by reduced spinothalamic function. To examine these possibilities, we studied 11 patients (ages 51-82 years) with unilateral central pain and with reproducible cerebral evoked vertex potentials in response to cutaneous stimulation of the normal side with pulses from an infra-red CO2 laser. All patients had normal tactile and kinesthetic sensation; one had slightly decreased vibratory sense bilaterally. ⋯ In contrast, laser stimulation of the affected side failed to evoke either N or P potentials in 6 patients, all of whom had lateralized increased thresholds for warm, heat pain, or deep pain, or reduced ratings of laser pulse sensation. Although 1 patient had increased ratings of laser pulse sensation, the amplitude of the LEP was always reduced on the side of increased pain or heat threshold in these CPS patients (Fisher exact test: P = 0.015). These results reflect primarily a deficit in spinothalamic tract function and do not suggest excessive CNS responses to synchronous activation of cutaneous heat nociceptors in patients with CPS.
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Randomized Controlled Trial Clinical Trial
The opposite effects of the opiate antagonist naloxone and the cholecystokinin antagonist proglumide on placebo analgesia.
Discovery of the involvement of endogenous opiates in placebo analgesia represents an important step in understanding the mechanisms underlying placebo response. In the present study, we investigated the effects of the opiate antagonist naloxone and the cholecystokinin antagonist proglumide on placebo analgesia in a human model of experimentally induced ischemic pain. First, we found that part of the placebo response was reversed by naloxone, confirming previous studies on the role of opioids in the placebo phenomenon. ⋯ The placebo effect can thus be modulated in two opposite directions: it can be partially abolished by naloxone and potentiated by proglumide. The fact that placebo potentiation by proglumide occurred only in placebo responders, but not in non-responders, suggests that activation of an endogenous opiate system is a necessary condition for the action of proglumide. These results suggest an inhibitory role for cholecystokinin in placebo response, although the low affinity of proglumide for cholecystokinin receptors does not rule out the possibility of other mechanisms.
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Comparative Study Clinical Trial
Active and passive coping strategies in chronic pain patients.
This study assessed the validity of active and passive coping dimensions in chronic pain patients (n = 76) using the Coping Strategies Questionnaire and the Vanderbilt Pain Management Inventory. The validity of active and passive coping dimensions was supported; passive coping was strongly related to general psychological distress and depression, and active coping was associated with activity level and was inversely related to psychological distress. In addition, the Coping Strategies Questionnaire was found to be a more psychometrically sound measure of active and passive coping than the Vanderbilt Pain Management Inventory.
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Comparative Study Clinical Trial Controlled Clinical Trial
Comparison between celiac plexus block and morphine treatment on quality of life in patients with pancreatic cancer pain.
Twenty-one patients with pancreatic cancer pain were studied to evaluate the effectiveness of celiac plexus block (CPB) on pain relief and quality of life (QOL), compared to the traditional NSAID-morphine treatment. The criteria were morphine consumption, visual analogue pain scale (VAS), performance status (PS) determined by medical and nursing staffs, and answers to QOL questionnaires. Morphine consumption, VAS, PS, and self-assessed QOL scores were taken when the administration of morphine was necessary for pain relief and those scores were used as control. ⋯ Self-assessed QOL scores did not ameliorate statistically after CPB; however, they did deteriorate remarkably in the patients treated only with morphine-NSAID during their survival periods, while they deteriorated only slightly in the CPB group. There were fewer side effects after CPB. These results indicate CPB does not directly improve QOL in patients with pancreatic cancer pain, but it may prevent deterioration in QOL by the long-lasting analgesic effect, limitation of side effects and the reduction of morphine consumption, compared to treatment only with NSAID-morphine.