Pain
-
Randomized Controlled Trial
Supra-additive effects of tramadol and acetaminophen in a human pain model.
The combination of analgesic drugs with different pharmacological properties may show better efficacy with less side effects. Aim of this study was to examine the analgesic and antihyperalgesic properties of the weak opioid tramadol and the non-opioid acetaminophen, alone as well as in combination, in an experimental pain model in humans. After approval of the local Ethics Committee, 17 healthy volunteers were enrolled in this double-blind and placebo-controlled study in a cross-over design. ⋯ Our study provides first results on interactions of tramadol and acetaminophen on experimental pain and hyperalgesia in humans. Pharmacodynamic modeling combined with the isobolographic technique showed supra-additive effects of the combination of acetaminophen and tramadol concerning both, analgesia and antihyperalgesia. The results might act as a rationale for combining both analgesics.
-
The rostral ventromedial medulla (RVM) is involved in facilitation of spinal nociceptive processing and generation of hyperalgesia in inflammatory and neuropathic pain models. We hypothesized that the bilateral hyperalgesia that develops after repeated intramuscular injections of acidic saline is initiated and maintained by activation of descending facilitatory pathways from the RVM. Male Sprague-Dawley rats were implanted with intracerebral guide cannulae into the nucleus raphe magnus (NRM) or the nucleus gigantocellularis (Gi). ⋯ However, neither cutaneous nor muscle hyperalgesia developed in the group treated with ropivacaine prior to the second intramuscular injection. Ropivacaine also significantly reversed the hyperalgesia in the group treated 24h after the second intramuscular acid injection. Thus, the RVM is critical for both the development and maintenance of hyperalgesia after muscle insult.
-
The aim of this study was to evaluate the construct validity and feasibility of a multidimensional electronic pain diary (e-Ouch(c)) in adolescents with juvenile idiopathic arthritis (JIA). Two descriptive studies with repeated measures were conducted between January and December 2005. Participants were drawn from a large metropolitan rheumatology clinic in a university affiliated pediatric tertiary care centre. ⋯ Pain ratings were significantly lower following joint injections with effect sizes in the low to moderate and moderate to high ranges at the first and second week post-injection, respectively. These findings provide evidence of the construct validity and feasibility of the e-Ouch(c) electronic diary in adolescents with JIA. Use of real-time data capture approaches should be considered in future studies of chronic arthritis.
-
Randomized Controlled Trial
Evaluating the efficacy of graded in vivo exposure for the treatment of fear in patients with chronic back pain: a randomized controlled clinical trial.
Psychological treatments for chronic pain, particularly those based upon cognitive behavioural principles, have generally been shown to be efficacious. Recently, a treatment has been developed based upon the fear-avoidance model of chronic musculoskeletal pain, which suggests chronic pain can be relieved by exposing the individual to movements and tasks that have been avoided due to fear of (re)injury. This graded in vivo exposure treatment has been found to be beneficial in case studies. ⋯ While only trend differences were observed for pain-related disability, patients in the graded in vivo exposure condition demonstrated (a) significantly greater improvements on measures of fear of pain/movement, fear avoidance beliefs, pain-related anxiety, and pain self-efficacy when compared to those in the graded activity condition, and (b) significantly greater improvements on measures of fear-avoidance beliefs, fear of pain/movement, pain-related anxiety, pain catastrophising, pain experience, and anxiety and depression when compared to those in the wait-list control condition. Additionally, patients in the graded in vivo exposure condition maintained improvements in these areas at one month follow-up. Implications of these findings for the treatment of individuals with chronic low back and other pain conditions are discussed.