Clinical Trials in Orofacial Neuralgias
Dextromethorphan
Cranial Nerve Diseases+13
+ Facial Nerve Diseases
+ Stomatognathic Diseases
Treatment Study
Summary
Study start date: December 1, 1997
Actual date on which the first participant was enrolled.Some of the clinical features of trigeminal and other facial neuralgias suggest that these painful disorders may be associated with sensitization of central nervous system neurons. Laboratory evidence has shown that central sensitization can be produced and maintained by excitatory amino acids (e.g. glutamate) acting on neurons at NMDA and AMPA/kainate receptor sites. Given this information, and the need for more effective treatments of orofacial neuropathic pain syndromes, two possible candidates worthy of study are 1) dextromethorphan, an NMDA receptor antagonist and 2) topiramate, an anticonvulsant drug with AMPA/kainate receptor blocking activity. Thus, the purpose of this study is to evaluate the efficacy and safety of topiramate (TPM) or high-dose dextromethorphan (DM) versus placebo in the treatment of pain in patients with trigeminal neuralgia (TN) and other orofacial neuropathic pain syndromes. We propose two 6 month studies respectively evaluating dextromethorphan (60 patients; at least 20 with TN, 20 with definite trigeminal nerve pathology and 20 with likely trigeminal nerve pathology) and topiramate (40 patients; at least 20 with TN, 20 with definite trigeminal nerve pathology). These will be double-blind randomized crossover designs comparing high-dose dextromethorphan (DM) versus lorazepam (LOR) (as an active placebo) OR topiramate versus inactive placebo. The primary study outcome measure (in both parts) will be overall daily pain assessed by Gracely pain intensity descriptors. Other recorded data will include adverse drug effects, the frequency, severity and duration of pain paroxysms and a questionnaire focusing on daily function (modification of the Brief Pain Inventory).
Protocol
This section provides details of the study plan, including how the study is designed and what the study is measuring.100 patients to be enrolled
Total number of participants that the clinical trial aims to recruit.Treatment Study
Eligibility
Researchers look for people who fit a certain description, called eligibility criteria: person's general health condition or prior treatments.Any sex
Biological sex of participants that are eligible to enroll.Healthy volunteers not allowed
If individuals who are healthy and do not have the condition being studied can participate.Conditions
Pathology
Criteria
Facial neuralgia, not explained by bone, soft tissue or mucosal lesions. Experiencing daily moderate pain or daily paroxysms of pain unremitting for at least 3 months. Previous trial of an antineuralgic medication. Patients entering the study on other analgesic medications must either continue them as a stable regimen throughout the study period or discontinue them 2 weeks prior to starting the initial pain diary. Adults aged 18 to 89. Serum laboratory results obtained at study entry: Liver function tests: ALT/AST less than 1.2 times upper limit of normal; Creatinine less than 1.5 times upper limit of normal; Negative serum betaHCG for women of childbearing age. Adequate birth control (e.g., oral contraceptives, Norplant) for all women of child-bearing age. Sufficient cognitive function and English language skills to complete questionnaires and communicate verbally with the nursing staff to permit titration of the study drugs. No presence of a painful condition as severe as, but distinct from their orofacial pain condition. No pregnant or lactating women. Patients must not have end-stage renal or hepatic disease. Patients must not have moderate to severe heart disease (MI within preceding year, unstable angina or congestive heart failure). No signs or symptoms of any central neurologic disorder (including seizures). No psychological/psychiatric disorder as identified by a pre-study entry psychiatric assessment. Patients must not have hypersensitivity or intolerance to dextromethorphan, topiramate or the active placebo. No chronic substance abuse, including alcoholism. Patients must have a primary physician. Subjects must not have received an experimental drug or used and experimental device within 30 days.
Study Centers
These are the hospitals, clinics, or research facilities where the trial is being conducted. You can find the location closest to you and its status.This study has 1 location
National Institute of Dental And Craniofacial Research (NIDCR)
Bethesda, United StatesOpen National Institute of Dental And Craniofacial Research (NIDCR) in Google Maps