Pain
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Randomized Controlled Trial Clinical Trial
Concentration-effect relationship of intravenous alfentanil and ketamine on peripheral neurosensory thresholds, allodynia and hyperalgesia of neuropathic pain.
Both mu opioid agonists and N-methyl-D-aspartate (NMDA) receptor antagonists are implicated in the regulation of neuropathic pain in post-nerve injury preclinical pain models. This study characterizes the effects of intravenously infused alfentanil (a mu-receptor agonist) and ketamine (an NMDA-receptor antagonist) on human neuropathic pain states, characterized by allodynia and hyperalgesia. Using diphenhydramine as the placebo, alfentanil and ketamine infusions were given in a randomized double-blind fashion 1 week apart via a computer-controlled infusion (CCI) pump that was programmed to target plasma levels of alfentanil at 25, 50 and 75 ng/ml and ketamine at 50, 100 and 150 ng/ml. ⋯ Therefore, clinical utilization of opioids with careful titration may be beneficial in post-nerve injury patients with partial deafferentation. With the absence of significant CNS side effects, the ketamine infusion not only demonstrated the well-documented spinal cord mechanism of the NMDA receptor, but the result of the current study also suggests that a peripheral mechanism of NMDA receptor may exist. The relationship between central sensitization and regulation of peripheral NMDA-receptor expression requires further investigation.
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Randomized Controlled Trial Clinical Trial
Treatment of severe pain from osteoarthritis with slow-release tramadol or dihydrocodeine in combination with NSAID's: a randomised study comparing analgesia, antinociception and gastrointestinal effects.
Opioids are increasingly used in the treatment of chronic non-malignant pain. The aim of this open-label, randomised, parallel group study was to compare analgesia and side-effects of two commonly used opioid analgesics, tramadol and dihydrocodeine, in long-acting formulations in 60 osteoarthritis patients with strong pain despite NSAID's. Dose titration based on effect was performed with the respective immediate release solutions given additionally to tramadol 100 mg bid and dihydrocodeine 60 mg bid during the first 4 days of the 1 month treatment. ⋯ We conclude rapid pain relief was achieved with both long-acting tramadol and dihydrocodeine with NSAID's in strong osteoarthritis pain. Minimal dose titration was required and side-effects were minor. Tramadol interfered less with intestinal function and showed greater antinociceptive action.
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Randomized Controlled Trial Clinical Trial
A cognitive-behavioral return-to-work program: effects on pain patients with a history of long-term versus short-term sick leave.
A cognitive-behavioral return-to-work focused program was evaluated in a randomized controlled design, and the effects were compared between two groups of women with musculoskeletal pain. One group of patients (n=36) had a history of long-term sick leave (>12 months) at the start of the program and the other (n=36) had a history of short-term sick leave (2-6 months). The outpatient treatment program, conducted by a psychologist, included 12 sessions with the primary aim to help the patients return-to-work. ⋯ The results showed that the cognitive-behavioral return-to-work program was more effective than the treatment-as-usual control condition in reducing the number of days on sick leave for patients on short-term sick leave, but not for patients on long-term sick leave. The treatment program also helped the patients on short-term sick leave to increase their ability to control and decrease pain and to increase their general activity level compared to the control condition. These results underscore the need for an early return-to-work focused rehabilitation to prevent long-term sick leave and disability.
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Randomized Controlled Trial Comparative Study Clinical Trial
Breakthrough cancer pain: a randomized trial comparing oral transmucosal fentanyl citrate (OTFC) and morphine sulfate immediate release (MSIR).
Oral transmucosal fentanyl citrate (OTFC); Actiq) is a drug delivery formulation used for management of breakthrough cancer pain. Previous studies with open-label comparisons indicated OTFC was more effective than patients' usual opioid for breakthrough pain. The objective of this study was to compare OTFC and morphine sulfate immediate release (MSIR) for management of breakthrough pain in patients receiving a fixed scheduled opioid regimen. ⋯ GP also favored OTFC and more patients opted to continue with OTFC than MSIR following the study. Somnolence, nausea, constipation, and dizziness were the most common drug-associated side effects. In conclusion, OTFC was more effective than MSIR in treating breakthrough cancer pain.
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Randomized Controlled Trial Clinical Trial
Habituation of the early pain-specific respiratory response in sustained pain.
Neurokinin-1 receptor and mu-opioid receptor agonists affect respiratory rhythm when injected directly into the preBötzinger brainstem complex, which is the hypothesized site for respiratory rhythmogenesis in mammals (Science 286 (1999) 1566). Early stress-induced analgesia (SIA) is naloxone-insensitive and as such considered independent of the activation of the mu-opioid system. Prolonged application of electrical shocks, however, produces analgesia that is mediated by the mu-opioid system (Science 208 (1980) 623). ⋯ In the early stage of pain, all monitored variables (respiration rate, minute ventilation volume, and inspiratory and expiratory flow rates) were elevated to statistically significant degrees when compared to measurements taken at baseline or during control infusion. Only respiration rate continued to be significantly elevated in sustained pain. We concluded that rhythmogenic neurons in the preBötzinger brainstem complex appear as the likely target for pro-nociceptive and anti-nociceptive input, explaining both the observed initial facilitation and subsequent habituation of respiration in early and sustained pain.