European journal of pain : EJP
-
Fixed-dose combination analgesics are used widely, and available both on prescription and over-the-counter. Combination drugs should provide more analgesia than with any single drug in the combination, but there is no evidence in humans about whether oral combinations have just additive effects, or are synergistic or even subadditive. We suggest that the measured result for the combination would be the summation of the absolute benefit increase (effect of active drug minus effect of placebo) of each component of a combination if effects were (merely) additive, and greater than the sum of the absolute benefits if they were synergistic. ⋯ Results showed that expected numbers needed to treat (NNT) for additive effects were generally within the 95% confidence interval of measured NNTs. This was true for combinations of paracetamol plus ibuprofen and paracetamol plus opioids in acute pain, and naproxen plus sumatriptan in migraine, but not where efficacy was very low or very high, nor combinations of paracetamol plus dextropropoxyphene. There was no evidence of synergy, defined as supra-additive effects.
-
The fundamental aspects of bone associated pain in humans are not fully understood. In this study pressure pain applied to the tibia bone was investigated experimentally in humans and by means of computer simulations. In humans, the pressure pain sensitivity and the relation between tissue indentation and pressure intensity were recorded by a computer-controlled pressure algometer with two different probe sizes (0.03 cm(2) and 1.0 cm(2)). ⋯ For both probes the strain peaked in adipose tissue at 0.29, and in the bone interface it was reduced by 3% (0.03 cm(2)) and 15% (1.0 cm(2)), respectively. For both probes the stress peaked at 235 kPa in skin layer, and in the deeper layers it was reduced to 50 kPa. Mechanosensitive nociceptors innervating the periosteum are ideally placed to mediate pain evoked by pressure stimulation on the tibia bone and small diameter probes may be optimal for assessing bone associated pain sensitivity.
-
Randomized Controlled Trial Multicenter Study
Peripartum pain management in opioid dependent women.
Increased pain sensitivity and the development of opioid tolerance complicate the treatment of pain experiencedby opioid maintained pregnantwomenduring delivery and the perinatal period. Theaim of the present study was to investigate differences in pain management of opioid maintained compared to nondependent pregnant women during delivery and the postpartum period. 40 deliveries of 37 opioid dependent women enrolled in a double-blind, double-dummy randomized controlled trial (RCT) examining the safety and efficacy of methadone (mean dose at the time of delivery = 63.89 mg) and buprenorphine (mean dose at the time of delivery = 14.05 mg) during pregnancy were analyzed and participants were matched to a non-dependent comparison group of 80 pregnant women. Differences in pain management (opioid and non-opioid analgesic medication) during delivery and perinatal period were analyzed. ⋯ Significantly higher nicotine consumption in the group of opioid dependentwomenhad a strong influence onthe retrieved results, and might be considered as an independent factor of altered pain experience. Differences in pain treatment became evident when comparing opioid maintained women to healthy controls. These differences might be based on psychosocial consequences of opioid addiction along with the lack of an interdisciplinary consensus on pain treatment protocols for opioid dependent patients.
-
Randomized Controlled Trial
Dose response of tramadol and its combination with paracetamol in UVB induced hyperalgesia.
Combining tramadol with paracetamol is an established analgesic treatment strategy. However, dosing and differential effects on peripheral and central hyperalgesia are still to be determined. After Ethics Committee approval, 32 volunteers have been included in this 2 phased, double blinded, placebo controlled, cross-over study. ⋯ Paracetamol also reduced secondary hyperalgesia, but no combination effect with tramadol could be shown. We conclude, in inflammatory hyperalgesia tramadol alone exerts only weak anti-hyperalgesia. Even adding a small dose paracetamol enhances thermal anti-hyperalgesia.
-
Multicenter Study
Using graded motor imagery for complex regional pain syndrome in clinical practice: failure to improve pain.
There is good evidence from studies conducted in a single-centre research setting for the efficacy of graded motor imagery (GMI) treatment, a complex physiotherapy intervention, to reduce pain in long-standing complex regional pain syndrome (CRPS). However, whether GMI is effective in clinical practice is not established. ⋯ The failure of our real-world implementation of GMI suggests that better understanding of both the GMI methodology and its interaction with other treatment methods is required to ensure that GMI research results can be translated into clinical practice. Our results highlight challenges with the translation of complex interventions for chronic pain conditions into clinical practice.