View clinical trials related to Hyperalgesia.
Filter by:The use of capsaicin as a potential analgesic drug for postoperative pain relies on the ability of capsaicin to induce membrane lysis of c-nerve fibers. In a previous randomized placebo controled blinded study of this effect we found a significant effect of capsaicin versus placebo. Before surgery all patients were examined by quantitative sensory testing to evaluate sensory function. In this study an identical sensory testing will examine if changes to the sensory function in capsaicin treated patients is identical to placebo treated patients.No new intervention will be performed
The goal of this study is to compare the changes that occur in sensation and chemical properties of the brain following SCI between individuals that experience chronic pain and those that do not, and between those with SCI and the able-bodied.
The study is a multi-modal multi-tissue human experimental pain study in 24 healthy volunteers. The study is a randomized cross-over study. The effect of 2 opioids will be compared on pain stimuli in skin, muscle an oesophagus. Hyperalgesia will be induced in skin and oesophagus, to sensitize these tissues. The pain thresholds before and after opioid administration will be compared. The hypothesis is that the difference in effect of the opioids is more pronounced in the presence of hyperalgesia. As hyperalgesia is a common phenomenon the clinic, the findings in this study may lead to a better understanding of the treatment of pain. The study will include an explorative study of the effect of Morphine of pain processing in the brain, this will provide us with new insight in the effect of the opioids of pain processing in the brain.
We propose performing a study in which we compare the effects of bupivacaine and fentanyl with a different drug combination − bupivacaine and clonidine. The principal research questions of the study are: 1. To compare the effect of clonidine (with bupivacaine), injected into the epidural space on the extent of hyperalgesia (abnormal pain/sensitivity in the uninjured skin surrounding the operation site) in patients undergoing operations for bowel disease, with that of fentanyl (with bupivacaine). 2. To compare the effect of clonidine (with bupivacaine), injected into the epidural space on the incidence of chronic pain 6 months after surgery for bowel disease, with that of fentanyl (with bupivacaine).
Postoperative pain after major surgery is consecutive not only to the nociceptive inputs coming from the surgical lesion, but also to peripheral and central neuronal sensitization. This lead to postoperative hyperalgesia and allodynia that are enhanced by the per operative use of high opioid doses. Anti-NMDA drugs have been reported as able to reduce this sensitization process and then to decrease acute morphine tolerance during the postoperative period. Nefopam has been lately shown to combine in experimental trials analgesic and anti hyperalgesic effects. The aim of this study is to compare anti-hyperalgesic effects of nefopam given either before incision and continuously for the following 48hours or starting from the end of the surgery and given for 48hours to a control group that would receive placebo for 48hours. Postoperative analgesia will be based on morphine PCA. Pain scores, hyperalgesia, allodynia, postoperative morphine consumption, and development of chronic pain will be the main criteria that will be evaluated during this study
GSK189254 is a highly potent histamine 3 (H3) receptor antagonist which has demonstrated efficacy in the reduction of mechanical hyperalgesia and allodynia in the chronic constriction injury pre-clinical model of neuropathic pain (NP). The mechanism of action of GSK 189254 in the pain model is hypothesised to be via enhanced release of monoamines in the central nervous system (CNS). A similar mechanism of action has also been shown for duloxetine. In this phase I study, the safety and efficacy of GSK189254 will be investigated in the electrical hyperalgesia (EH) model in healthy volunteers to build confidence that the preclinical efficacy demonstrated by this compound will translate into patients. This study will be conducted as a double-blind, double-dummy, placebo-controlled, incomplete block, two period crossover study. Up to 40 healthy male or female volunteers, aged 18-45 years old, will be randomised into the study in order to achieve 32 evaluable subjects. Subjects will undergo two 3-week treatment periods and will be randomised to receive placebo and either GSK189254 (up to 100µg once daily) or duloxetine (up to 60mg daily). There will be a one week washout between treatment periods. The effects of repeated oral dosing of GSK189254 and duloxetine on secondary hyperalgesia in the EH model will be determined. Subject: GSK189254, Neuropathic pain (NP), H3 antagonist, duloxetine, Electrical hyperalgesia, Phase I, Healthy volunteers, Double blind, Safety, tolerability.
To determine the effects of Lidocaine patch on the pain and hyperalgesia induced by intradermal capsaicin
In the proposed study, we will build upon our previous studies validating and characterizing hyperalgesia in MM samples to explore it's underlying mechanism from a pharmacological perspective. Utilizing a double-blind, placebo-controlled designs, the proposed work will evaluate the ability of dextromethorphan , an N-methyl-D-aspartate (NMDA)-antagonists to diminish or reverse the opioid-induced hyperalgesia complicating the pain states suffered by MM patients. Specifically, in a sample of MM patients, dextromethorphan, theorized to interfere with the development of opioid-induced hyperalgesia will be evaluated for its ability to ameliorate or diminish the opioid-induced hyperalgesia in these patients as reflected by changes on pain threshold and tolerance to both cold-pressor and electrical pain, at peak and trough methadone blood levels. The results of this work will not only provide pharmacologic insight into the mechanisms underlying poor pain tolerance in this at-risk population, but also direction for the medical management of pain complicated by opioid-induced hyperalgesia.
The aim of this randomized placebo-controlled study is to evaluate the effects of analgetics for neuropathic pain on mechanical hyperalgesia as a kind of evoked pain. Therefore the number of responders and non-responders on pregabalin will be evaluated in respect of mechanical hyperalgesia (stimulus-response-function (SRF) on static punctual stimuli evoking pain determined via pinprick). The hypothesis is that in the placebo group the amount of non-responders is increased.
After surgery, sensitization and hyperexcitability of central nervous system result in acute and long lasting postoperative pain. It has been shown that N-methyl-D-aspartate (NMDA) receptors antagonist (such as ketamine) prevent this adverse neuroplasticity and potentiate analgesic drugs efficacy. Polyamines (putrescine, spermidine, spermine) are essential components of cells functioning and are also known as allosteric modulators of NMDA receptors. In animal studies, polyamine-free diet has confirmed these antinociceptive properties. This research aims at evaluating anti hyperalgesic properties of polyamine-free diet in women operated on breast cancer versus kétamine