View clinical trials related to Hyperalgesia.
Filter by:The findings from preclinical animal models confirm the peripheral anti-inflammatory/analgesic activity of GW406381 and also suggest contribution of a central site of action to the anti-hyperalgesic efficacy that may not be shared by other COX-2 inhibitors. A central action is consistent with distribution of GW406381 into the CNS in animals. Furthermore, preliminary data from a positron emission tomography study in which 6 healthy male volunteers received a tracer dose of 11C labelled GW406381 indicate that GW406381 is rapidly absorbed into the central nervous system in man.
Tis study was designed to test the hypothesis that pretreatment with valdecoxib, prior to injury could reduce or prevent the development of secondary hyperalgesia around the area of primary injury. A heat/capsaicin model of induced hyperalgesia was tested in healthy volunteers in a randomized, double blind, cross-over trial of a single dose of 40 mg vadecoxib versus control. Subjects rated pain intesnsity and unpleasantness following heat stimulation of the forearm, the area of hyperalgesia was also mapped over the course of the experiment.
Opiates such as morphine are the cornerstone medications for the treatment of moderate to severe pain. Recent evidence suggests that pain patients on chronic opioid therapy become more sensitive to pain (hyperalgesia) over time. There is also a long-standing notion that analgesic tolerance to opioids (habituation) develops during chronic use even though this phenomenon has never been prospectively studied. Our specific aims propose to prospectively test the hypotheses that; 1) Pain patients on chronic opioid therapy develop dose-dependent tolerance and/or hyperalgesia to these medications over time, 2) Opioid-induced tolerance and hyperalgesia develop differently with respect to various types of pain, 3) Opioid-induced hyperalgesia occurs independently of withdrawal phenomena, and 4) Opioid-induced tolerance and hyperalgesia develop differently based on gender and/or ethnicity. This proposed study will be the first quantitative and prospective study of tolerance and hyperalgesia in pain patients and will have important implications for the rational use of opioids in the treatment of chronic pain.
The purpose of this study is to determine whether or not inhaled marijuana displays any pain-relieving properties on experimentally-induced pain.
Individuals who reduce or stop use of opioid medications are at risk for developing hyperalgesia, which is an increased sensitivity to pain. This study will compare the effectiveness of dextromethorphan, gabapentin, and oxycodone at reducing hyperalgesia in individuals addicted to opioids who are concurrently receiving methadone treatment.
The primary aim is to determine whether perioperative NMDA-receptor antagonism has differential effects on postoperative pain, hyperalgesia and morbidity in younger and older patients. In order to achieve this aim, the researchers propose to conduct the first randomized, double-blind placebo-controlled study designed to investigate age differences in the effects of perioperative oral administration of an NMDA-receptor antagonist (amantadine) in men undergoing radical prostatectomy. In addition, age differences in psychosocial factors and the pharmacological properties of amantadine and morphine will be measured to control for, and clarify, their contribution to the differences found. The specific objectives of the study are to: 1. investigate the effects of perioperative NMDA receptor blockade on postoperative hyperalgesia, pain and analgesic consumption in young and elderly men 2. assess age differences in the intensity and course of secondary hyperalgesia after surgery
Noncardiac chest pain (NCCP) is a common clinical problem worldwide. In Hong Kong, it has been estimated that about 20% of patients with chest pain are misdiagnosed to have coronary heart disease. Despite its benign nature, this condition causes anxiety, impairs quality of life and consumes a substantial amount of healthcare resources. While acid reflux and motility disorder in the esophagus are often attributed as the cause of NCCP, visceral hyperalgesia of esophagus is now recognized to play a central role in the pathogenesis of this condition. This research project aims to evaluate the role of visceral hyperalgesia in Chinese patients with NCCP. NCCP patients will be evaluated for the prevalence of gastroesophageal reflux disease and esophageal motility disorder by endoscopy, manometry and pH study. The visceral sensory and pain thresholds of these patients will be compared with asymptomatic controls.
The effect of baclofen (GABAB agonist), diltiazem (muscle relaxant) and placebo will be compared in a double-blinded randomized study for the treatment of NCCP. Cerebral cortical, brainstem and spinal evoked potentials before and after treatment will be evaluated. Results of this study will shed lights on pathogenesis and treatment of NCCP in Chinese.We hypothesize that Baclofen alleviates visceral hyperalgesia in NCCP patients by suppressing afferent sensory pathway.
The purpose of this study is to learn more about the role of genetics in pain sensitivity. Pain perception varies widely among individuals, and information gained from this trial may lead to better methods of preventing and controlling pain. The study consists of two parts, described below. All enrollees will participate in part 1; patients needing oral surgery for removal of third molars may also participate in part 2. Normal volunteers, oral surgery patients, and family members of both groups may be eligible for this study. Part 1 -Sensitivity testing for hot and cold. Participants will rate their pain response to hot and cold stimuli on a scale from "no pain" to the "worst pain imaginable." Heat sensitivity is measured using a small probe placed on the skin for a few seconds. The hottest temperature tested may cause pain for a few seconds but will not produce a burn. Response to cold is measured by placing the hand in cold water for up to 3 minutes and occasionally flexing the fist. Participants will rate their pain level every 15 seconds. In addition to the testing, a blood sample will be drawn to examine for genes related to pain. Part 2 - Oral surgery. Patients will have their third molar removed under a local anesthetic (lidocaine) injected in the mouth and a sedative (Versed) given through a vein in the arm. A small tissue biopsy will be taken from the tissue over one of the third molars. Patients will stay in the clinic for up to 7 hours after surgery while the anesthetic wears off and will rate any pain they may have according to the rating scale used in Part 1 of the study. Pain medication (ketorolac, or Toradol) will be given when needed, and patients will complete pain questionnaires for 3 hours after the drug is given to rate its effectiveness. Patients will receive additional pain relievers, if needed. A second biopsy on the side opposite the first will be taken under local anesthetic to measure changes in chemical signals produced in response to the surgery.
This study will examine how the brain processes pain signals and how the different parts of the brain work with each other in response to painful stimuli. A better understanding of how people experience pain may be helpful in developing more effective treatments. Healthy normal volunteers, patients requiring third molar (wisdom tooth) extraction, and patients with persistent pain due to disease, injury or other reason may be eligible for this study. Participants will receive one or more of the following sensory stimuli, which may cause brief discomfort or pain: - Heat/Cold - applied by an electronically controlled device that touches the skin, or by temperature-controlled water baths, or by a thermally controlled brass cylinder the subject grasps - Capsaicin (active ingredient in hot chili peppers) - injected in a small volume of fluid under the skin or into a muscle - Mechanical stimulation - brushings or vibrations that do not normally cause pain - Ischemic stimulation - inflation of a blood pressure cuff on the arm or leg for up to 30 minutes These stimuli will be applied both before and during positron emission tomography (PET) scanning. This test shows which parts of the brain are active and which are not and is important for studying how different parts of the brain work together to feel and react to specific sensations. For this procedure, the subject lies on a table in the PET scanner while a series of scans are taken during different sensory conditions. At the beginning of each scan, radioactive water is injected into an arm vein through a catheter (a thin plastic tube). A special camera records the arrival and disappearance of the radiation in various brain areas, creating a picture of the brain's activity in various regions. Oral surgery patients may have PET scans both before and after their wisdom tooth extraction. Alfentanil, a commonly used narcotic pain reliever, will also be given during the PET procedure to determine how the brain responds to sensory stimuli while under the effects of a pain killer. Participants will also have a magnetic resonance imaging (MRI) scan of the brain to help interpret the PET results. MRI uses a magnetic field and radio waves to show structural and chemical changes in tissues. During the scan, the subject lies on a table in a cylindrical machine (the scanner). He or she can speak with a staff member via an intercom system. Some sensory studies may require placing an arterial and/or intravenous line. Following injection of a local anesthetic, a catheter is placed in an artery in the arm. At regular intervals during various sensory stimuli, small blood samples are drawn from the artery to measure blood gases and other substances. Samples may also be drawn from a catheter placed in a vein. Subjects may also have ultrasound monitoring to evaluate blood flow in the arteries, veins and brain. A gel is spread over the skin above the blood vessel and a hand-foot-and-mouth device is placed on the gel. The device emits high-frequency sound waves to produce a picture of the speed of blood flow in the artery and the diameter of the vessel.