Active clinical trials for "Hyperalgesia"

Opioids has been reported to cause hyperalgesia. Opioid induced hyperalgesia (OIH) is defined as paradoxically lowering the threshold of pain after the exposure of opioid. Remifentanil is a short acting opioid that is commonly used during anesthesia and surgery. However, OIH was reported to occur after surgery when large amount of remifentanil was administered. On the other hand, nefopam is a centrally acting, non-opioid analgesic. Nefopam has been reported to have analgesic and anti-hyperalgesic effect. The investigators hypothesized that nefopam administration could prevent OIH or reduce the severity of OIH. Therefore, the objective of the study is to find out the effect of nefopam on remifentanil induced hyperalgesia in patients undergoing laparoscopic abdominal surgery.

Hyperbaric oxygen may reduce neurophatic pain and promote wound healing. Established anti inflammatory effects of HBO may contribute to this effect. In a previous publication the investigators studied the effects of HBO on secondary hyperalgesia using a well established heat injury model. In a new - blinded study design, the investigators wish to investigate and- or confirm previous results, i.e. that HBO therapy reduce secondary hyperalgesia and improving therapy of severe pain conditions.

The purpose of this study was to follow a person's response to experimental pain after multiple consecutive exposures to alfentanil or diphenhydramine to see if the person can tolerate the pain more, less, or the same at the end of the study.

The purpose of this study is to evaluate the efficacy of Sativex® compared with placebo in relieving peripheral neuropathic pain associated with allodynia.

Gabapentin pretreatment may reduce hyperalgesia occurring at the second surgery in serial, bilateral cataract surgery.

A multicenter, randomized, open-label, active controlled pragmatic clinical trial that evaluates the safety and efficacy of S (+) -ketamine for postoperative acute pain in children in perioperative settings.

Evidence to support the effectiveness of ongoing opioid therapy for the treatment of chronic non-malignant pain is lacking. In fact, data suggest that patient outcomes improve when tapered off opioid analgesics. To better understand the role opioid therapy plays in the experience of pain, we will study measured pain sensitivity in opioid dependent patients over the course of and 3 months following a standardized opioid taper. By isolating the effect of opioid taper in patients without pain, preliminary evidence of effect size can be used to guide clinicians treating patients with chronic pain.

Opioid analgesic drugs are the main treatment of patients during anesthesia. Although highly effective, their use is not without problems. One is the increasing requirement of these address the same nociceptive stimulus. Opioid induced hyperalgesia could be an explanation studies in animal models. Through mechanisms where N-methyl-D-aspartate receptors, glutamatergic system disturbances and changes in intracellular calcium regulation involved. The hyperalgesia induced by intrathecal opioids is controversial. The investigators propose a model study in patients undergoing cesarean section to study the secondary hyperalgesia induced based on the study of nociceptive thresholds with two methods opioids: Von Frey filaments and digital algometer. If intrathecal fentanyl is used in spinal anesthesia for elective cesarean section, then, an increase in sensitivity will occur. This increase can be measured by von Frey filaments, expressed in increased requirement clinically opioids.

Opioid Induced Hyperalgesia (OIH) is an entity than has been demonstrated in healthy volunteers and in animal models. Is defined as an increase in the perception to painful stimuli, increasing the opioid requirements and diminishing the pain thresholds to stimuli. The apparition of OIH is also related to the exposure to opioids during surgery, depending of the dose, the time of exposition and the type of opioid. This condition can be modulated, specially in the perioperative context. It has been seen in healthy volunteers and in animal models, than the use of propranolol can modulate this phenomena, diminishing the postoperative requirements of analgesia. It is also unknown, the dose of propranolol required to modulate adequately OIH. The objective of this work is to evaluate the efficacy of propranolol in the modulation of opioid induced hyperalgesia, with lower postoperative requirements of analgesia rescue.

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.