View clinical trials related to Pain.
Filter by:The effectiveness of local anesthetics is reduced if inflammation is present, making it difficult to control pain during such procedures as root canals and wisdom teeth removal. This set of studies will assess the effectiveness of the opioid (synthetic narcotic) fentanyl in enhancing the local anesthetic lidocaine (delivered with epinephrine) when used on inflamed molar teeth. In the first study, a topical anesthetic patch or a placebo will be placed on the gum tissues next to four or five lower posterior teeth. The patch will removed at either 5, 10, or 15 minutes. An electronic test that sends a light electronic impulse into the tooth, lip sensitivity testing ("Is your lip numb?"), and discomfort reports will be started immediately after removal of the patch and repeated every 5 minutes for 30 minutes. An oral surgeon will then remove the patient's wisdom teeth (tooth). In the second and third studies, a topical anesthetic will be placed on the gum tissue. An electronic test that sends a light electronic impulse into the tooth, lip sensitivity testing ("Is your lip numb?"), and discomfort reports will be started and done several times throughout the test. Then two small openings, one on each side of the tooth, will be drilled into the bony tissues surrounding the tooth. A narcotic drug fentanyl or a placebo drug will be delivered through these openings, allowing placement of the drug next to the nerves that are difficult to numb. Lidocaine, along with a small amount of epinephrine, will be delivered. An oral surgeon will then remove the patient's wisdom teeth or tooth (study 2) or do a root canal (study 3). In the fourth study, a topical anesthetic will be placed on the gum tissue. Then two small openings, one on each side of the tooth, will be drilled into the bony tissues surrounding the tooth. A narcotic drug fentanyl or a placebo drug will be delivered through these openings. Lidocaine, along with a small amount of epinephrine, will be delivered at one of three rates (15 patients for each rate). Blood pressure, heart rate, and breathing rate will be taken before the topical anesthetic patch is applied, 2 minutes after, and every 5 minutes for the next 45 minutes. Blood samples will be taken 6 times over the course of 60 minutes. When testing is complete, an oral surgeon will remove the wisdom teeth (tooth). One month later, blood samples will be taken using a different drug delivery method in order to compare results.
Phantom pain refers to the sensation of pain felt by patients who have had a limb amputated. The treatment of phantom pain is often disappointing and is unable to provide adequate relief to the patients. The area of the brain involved (posterior parietal cortex [PPC]) is found on the opposite side of the amputated limb. For example, if a patient has the right arm amputated, the left posterior parietal cortex is involved in the phantom pain. Researchers believe that if they can decrease activity in the posterior parietal cortex they may be able to reduce phantom pain. Researchers plan to use low frequency (1 Hz) transcranial magnetic stimulation (TMS) to decrease the excitability of the PPC opposite the side of the amputated limb. TMS involves the placement of a cooled electromagnet with a figure-eight coil on the patient's scalp and turning on the magnetic flux. This permits non-invasive, relatively localized stimulation of the surface of the brain (cerebral cortex). When an area of the brain is stimulated a period follows when that area cannot be stimulated again. In this case, researchers plan to use TMS to stimulate the PPC in order to decrease the level of excitability there.
This study will evaluate the safety and effectiveness of two drugs-dextromethorphan and topiramate-in treating orofacial (mouth and face) pain. Dextromethorphan, a commonly used cough suppressant, and topiramate, an anti-seizure medicine, block certain receptors on brain and spinal nerve cells that may cause the cells to produce electrical discharges and pain. Patients 18 years of age and older with oral and facial pain with trigeminal nerve damage and who have had pain daily for at least 3 months may be eligible for this study. Candidates will be screened with a medical history, physical examination, blood tests and psychiatric evaluation. These results will serve as baseline values for participants. Those enrolled in the study will take either dextromethorphan or topiramate in a 2-part study as follows: Dextromethorphan In Part 1, patients will take dextromethorphan and lorazepam (a commonly used anti-anxiety drug) separately in two 6-week periods. (Lorazepam is used in this study as an "active placebo" for comparison with dextromethorphan. An active placebo is a drug that does not work for the problem being studied but whose side effects are like those of the test drug.) They will take dextromethorphan for 4 weeks to determine the maximum tolerated dose (the highest dose that does not cause troubling side effects) and will stay on that dose for the remaining 2 weeks. Then they will repeat this process with lorazepam. Patients who respond to either drug may continue with Part 2 of the study, which compares these two drugs four more times to confirm the response seen in Part 1. In Part 2, the maximum tolerated dose will be determined in a 2-week period and that dose will be continued for another 2 weeks. This procedure will be repeated eight times. Throughout the study, patients will keep a daily pain diary. They will be contacted by telephone 2 to 3 times a week during dose escalation to check for side effects. At the end of each of the two 6-week periods in Part 1 and at the end of each 4-week period in Part 2 of the study, patients will have a 1-hour clinic visit. Participants who live more than a few hours' drive from NIH will have a full telephone follow-up evaluation instead of the clinic visits. Topiramate Patients who receive topiramate will follow a plan similar to that described above for dextromethorphan, with the following exceptions. They will take topiramate and an inactive placebo (a look-alike pill that has no active ingredients) in two separate 12-week periods. Patients' maximum tolerated dose will be determined in the first 8 weeks and they will stay on that dose for the remaining 4 weeks of each period. Patients who respond to the medication in Part 1 may continue with Part 2 to confirm the response. Part 2 consists of six 6-week periods. The first 4 weeks of each will be used to determine the maximum tolerated dose and the patient will remain on that dose for the next 2 weeks. Patients will keep a daily pain diary and will be contacted by phone 2 to 3 times a week while doses are being increased. Patients who complete Part 2 of the topiramate study may participate in another phase of the study that will last for 2 years. Those who continue for this phase will take topiramate for the 2-year period. They will be followed regularly by a study nurse and will come to NIH every 6 months for a follow-up visit.
This study will evaluate the effectiveness of the non-steroidal anti-inflammatory drug flurbiprofen (Ansaid® (Registered Trademark)) in relieving pain following oral surgery. Flurbiprofen is approved by the Food and Drug Administration for treatment of arthritis pain. Patients 16 years of age and older requiring third molar (wisdom tooth) extraction may be eligible for this study. Patients will undergo oral surgery to remove two lower third molar teeth. Before surgery, they will be given a local anesthetic (lidocaine with epinephrine) injected in the mouth and a sedative (Versed) infused through a catheter (thin plastic tube) placed in an arm vein. At the time of surgery, patients will also be given flurbiprofen or a placebo formulation (look-alike substance with no active ingredient) directly into the extraction site and a capsule that also may contain flurbiprofen or placebo. One in seven patients will receive only placebo. All patients will fill out pain questionnaires and stay in the clinic for up to 6 hours for observation of bleeding and medication side effects. Patients who do not have satisfactory pain relief from the test medicine after surgery may request a standard pain reliever. A small blood sample will be collected during surgery and at 15 minutes, one-half hour and 1, 2, 3, 4, 5, 6, 24 and 48 hours after surgery to measure flurbiprofen blood levels. A total of 33 ml (about 2 tablespoons) of blood will be drawn for these tests. Samples collected on the day of surgery will be drawn from the catheter used to administer the sedative; the 24- and 48-hour samples will be taken by needle from an arm or hand vein. Urine samples will also be collected between 4 and 6 hours after surgery and again at 24 and 48 hours after surgery.
This study will attempt to develop and validate improved subjective measures of pain sensation and use these measures to evaluate pain sensitivity in patients. Normal healthy volunteers and dental patients undergoing third molar extraction may be eligible for this study. Participants will undergo the following procedures: Volunteers: Volunteers will participate in two 90-minute sessions in which they will receive and rate four heat stimuli per minute applied to the skin for a maximum of 36 minutes. The heat stimuli range from 37° (Degree)C to 51° (Degree)C (99° (Degree) F to 124° (Degree) F) and last 2 to 3 seconds. A drug commonly used in dental treatments may be administered during the second session. This will be either a maximum of 0.15 mg fentanyl, a short-acting narcotic pain killer, or a maximum of 5 mg saline, an inactive substance (placebo). Dental patients: Dental patients will participate in two 60-minute sessions. The first session will be on the day before the third molar extraction, and the second session will be immediately before the dental procedure. The heat stimulus procedure will be identical to that described above for normal healthy volunteers.
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.