Pain
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Efforts to examine the process and risk of developing chronic back pain have relied generally upon retrospective study of individuals with already established pain. In an alternative approach to understanding the clinical course and evolution of low back disorders, a cohort of 76 men experiencing their first episode of back pain was assessed prospectively at 2, 6 and 12 months following pain onset. Standard measures of pain (Descriptor Differential Scale: DDS), disability (Sickness Impact Profile: SIP), and distress (Beck Depression Inventory: BDI) were employed to classify the sample into five groups: Resolved, Pain Only, Disability/Distress Only, Pain and Mild Disability/Distress, and Clinical Range. ⋯ Comparison of those classified as 'improvers' with those who did not improve from 2 to 12 months showed similar findings. The clinical course of first onset back pain may be prolonged for many patients, and involves a continuum of related disability and distress. Individuals at risk for marked symptoms 1 year after an initial episode of back pain can be identified early, and prompt treatment might reduce the risk of pain chronicity.
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The management of severe tumor-related pain in the patient with cancer may be problematic. Systemically administered opioids remain the cornerstone of treatment for moderate to severe cancer pain, while parenteral routes should be considered for patients who require rapid onset of analgesia, and for highly tolerant patients whose dose requirements cannot be conveniently administered. The use of intravenous methadone by patient controlled analgesia (PCA) is attractive for the management of severe, intractable cancer pain and may offer some advantages over morphine. We describe the safe and effective use of high-dose intravenous methadone by PCA and continuous infusion for a patient with intractable tumor-associated cancer pain who experienced inadequate pain control and dose-limiting side-effects with high-dose intravenous morphine.
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Randomized Controlled Trial Clinical Trial Controlled Clinical Trial
Opiate and H1 antagonist effects on histamine induced pruritus and alloknesis.
Itching is a well known side-effect of opiate therapy. To gain insight into the possible contribution of opiate receptors to itching we compared the antipruritic effect of naltrexone (Nemexin), an opiate antagonist, to an H1-receptor antagonist and to placebo. In a double blind cross-over study on 15 healthy volunteers, 25 mg naltrexone or placebo was orally given 60 min prior to a histamine stimulus. ⋯ Both naltrexone and cetirizine significantly diminished histamine induced itching. In contrast to placebo and cetirizine, naltrexone abolished alloknesis completely in four of 15 volunteers and in the others alloknesis was greatly reduced after naltrexone. Since vascular reactions to histamine are of peripheral origin, whereas alloknesis depends on central nervous mechanisms, our findings suggest a pronounced centrally mediated action of naltrexone on histamine induced pruritus.
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The purpose of this review was to identify and analyze the controlled clinical trial data for peripheral neuropathic pain (PNP) and complex regional pain syndromes (CRPS). A total of 72 articles were found, which included 92 controlled drug trials using 48 different treatments. The methods of these studies were critically reviewed and the results summarized and compared. ⋯ The methods scores were higher (P < 0.01) for the PNP trials (66.2 +/- 1.5, n = 66) than the CRPS trials (57.6 +/- 2.9, n = 26). The CRPS trials tended to use less subjects and were less likely to use placebo controls, double-blinding, or perform statistical tests for differences in outcome measures between groups. There was almost no overlap in the controlled trial literature between treatments for PNP and CRPS, and treatments used in both conditions (intravenous phentolamine and epidural clonidine) had similar results.
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Results from laboratory and naturalistic studies have demonstrated decreased subjective pain ratings in hypertensives and individuals at risk for hypertension. Based on previous evidence that the nociceptive withdrawal reflex may provide an objective index of pain threshold in humans, the present study examined the intensity of sural nerve stimulation required to elicit nociceptive withdrawal in offspring of hypertensives and normotensives. Participants included 60 men and 56 women who were normotensive, 18-23 years of age, and predominately Caucasian. ⋯ Second, offspring of hypertensives endured significantly more intense stimulation before reporting pain. Third, both parental history of hypertension and resting systolic blood pressure were significant independent predictors of stimulation intensity at nociceptive withdrawal reflex and subjective pain thresholds. These results confirm and extend previous observations of an association between risk for hypertension and hypoalgesia, and suggest that hypoalgesia should be examined as a potential predictor of progressive blood pressure increases in individuals at risk for hypertension.