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Dextromethorphan Versus Placebo for Neuropathic Pain

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
 
ClinicalTrials.gov Identifier: NCT00001344
Recruitment Status : Completed
First Posted : December 10, 2002
Last Update Posted : March 4, 2008
Sponsor:
Information provided by:
National Institutes of Health Clinical Center (CC)

Brief Summary:
In our current clinical trial, we are comparing the effects of two NMDA receptor antagonists to placebo in patients with painful distal symmetrical diabetic neuropathy or post-herpetic neuralgia. The treatments in this three-period crossover study are dextromethorphan, up to 920 mg/day (about 8 times the antitussive dose), memantine, 30-50 mg/day, and placebo. Memantine is an NMDA antagonist used in Europe to treat Parkinson's disease and Alzheimer's disease. The underlying hypothesis, based on studies of painful neuropathies in animal models, is that neuropathic pain is caused largely by sensitization of central nervous system neurons caused by excitatory amino acid neurotransmitters, acting largely through NMDA receptors. A previous small trial of dextromethorphan suggested efficacy in diabetic neuropathy pain. The study requires one visit to the NIH outpatient Pain Research Clinic, and consists of three 9-week treatment periods. Patients who respond to one of the medications will be invited to participate in further controlled studies of the medication followed by up to several years of open-label treatment under continued observation.

Condition or disease Intervention/treatment Phase
Diabetic Neuropathies Herpes Zoster Neuralgia Drug: dextromethorphan Phase 2

Detailed Description:
In our current clinical trial, we are comparing the effects of two NMDA receptor antagonists to placebo in patients with painful distal symmetrical diabetic neuropathy or post-herpetic neuralgia. The treatments in this three-period crossover study are dextromethorphan, up to 920 mg/day (about 8 times the antitussive dose), memantine, 30-50 mg/day, and placebo. Memantine is an NMDA antagonist used in Europe to treat Parkinson's disease and Alzheimer's disease. The underlying hypothesis, based on studies of painful neuropathies in animal models, is that neuropathic pain is caused largely by sensitization of central nervous system neurons caused by excitatory amino acid neurotransmitters, acting largely through NMDA receptors. A previous small trial of dextromethorphan suggested efficacy in diabetic neuropathy pain. The study requires one visit to the NIH outpatient Pain Research Clinic, and consists of three 9-week treatment periods. Patients who respond to one of the medications will be invited to participate in further controlled studies of the medication followed by up to several years of open-label treatment under continued observation.

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Study Type : Interventional  (Clinical Trial)
Enrollment : 129 participants
Primary Purpose: Treatment
Official Title: Dextromethorphan Versus Placebo for Neuropathic Pain
Study Start Date : March 1993
Study Completion Date : February 2001

Resource links provided by the National Library of Medicine

MedlinePlus Genetics related topics: Shingles





Information from the National Library of Medicine

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Ages Eligible for Study:   Child, Adult, Older Adult
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Criteria

Patients must be over 18 years of age.

Patients must have a definite diagnosis of diabetic neuropathy or post herpetic neuralgia or a diagnosis of neuropathic pain of various etiologies other than diabetic neuropathy or post herpetic neuralgia.

Duration of symptoms must be at least 3 months.

Severity of pain must be at least mild, if constant; or at least moderate, if intermittent and at least 2 hours duration a day.

Patients using tricyclics, narcotics, or antiseizure medications, must keep the drug dosages constant throughout the study.

No patients with unstable disease process; i.e., angina pectoris, accelerated hypertension, recent stroke or transient cerebral ischemia, uncontrolled seizures.

No pregnant or lactating women. Women of child bearing potential must use birth control pills, intrauterine device, or barrier contraceptive devices.

No history of significant drug abuse or PCP use. No history of IV drug abuse, prescription drug abuse, or alcoholism.

No significant liver or kidney disease.

No MAO inhibitors.

No cognitive impairment or language difficulty as judged by difficulty completing pain diary, medical history, or telephone conversation.

Patients must not have any other chronic pain condition that gives them pain greater than the neuropathy pain.


Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00001344


Locations
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United States, Maryland
National Institute of Dental And Craniofacial Research (NIDCR)
Bethesda, Maryland, United States, 20892
Sponsors and Collaborators
National Institute of Dental and Craniofacial Research (NIDCR)
Publications:
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ClinicalTrials.gov Identifier: NCT00001344    
Other Study ID Numbers: 930114
93-D-0114
First Posted: December 10, 2002    Key Record Dates
Last Update Posted: March 4, 2008
Last Verified: March 2000
Keywords provided by National Institutes of Health Clinical Center (CC):
Diabetes Mellitus
Diabetic Neuropathy
Memantine
NMDA Receptor Antagonists
Neuropathic Pain
Neuropathy
Post-Herpetic Neuralgia
Shingles
Additional relevant MeSH terms:
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Herpes Zoster
Neuralgia
Diabetic Neuropathies
Peripheral Nervous System Diseases
Neuromuscular Diseases
Nervous System Diseases
Pain
Neurologic Manifestations
Diabetes Complications
Diabetes Mellitus
Endocrine System Diseases
Varicella Zoster Virus Infection
Herpesviridae Infections
DNA Virus Infections
Virus Diseases
Dextromethorphan
Antitussive Agents
Respiratory System Agents
Excitatory Amino Acid Antagonists
Excitatory Amino Acid Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action
Physiological Effects of Drugs