Dextromethorphan Versus Placebo for Neuropathic Pain

This study has been completed.
Sponsor:
Information provided by:
National Institutes of Health Clinical Center (CC)
ClinicalTrials.gov Identifier:
NCT00001344
First received: November 3, 1999
Last updated: March 3, 2008
Last verified: March 2000
  Purpose

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 Intervention Phase
Diabetic Neuropathies
Herpes Zoster
Neuralgia
Drug: dextromethorphan
Phase 2

Study Type: Interventional
Study Design: Endpoint Classification: Safety/Efficacy Study
Primary Purpose: Treatment
Official Title: Dextromethorphan Versus Placebo for Neuropathic Pain

Resource links provided by NLM:


Further study details as provided by National Institutes of Health Clinical Center (CC):

Estimated Enrollment: 129
Study Start Date: March 1993
Estimated Study Completion Date: February 2001
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.

  Eligibility

Genders Eligible for Study:   Both
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.

  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00001344

Locations
United States, Maryland
National Institute of Dental And Craniofacial Research (NIDCR)
Bethesda, Maryland, United States, 20892
Sponsors and Collaborators
  More Information

Publications:
ClinicalTrials.gov Identifier: NCT00001344     History of Changes
Other Study ID Numbers: 930114, 93-D-0114
Study First Received: November 3, 1999
Last Updated: March 3, 2008
Health Authority: United States: Federal Government

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:
Diabetic Neuropathies
Herpes Zoster
Neuralgia
DNA Virus Infections
Diabetes Complications
Diabetes Mellitus
Endocrine System Diseases
Herpesviridae Infections
Nervous System Diseases
Neurologic Manifestations
Neuromuscular Diseases
Pain
Peripheral Nervous System Diseases
Signs and Symptoms
Virus Diseases
Dextromethorphan
Antitussive Agents
Central Nervous System Agents
Excitatory Amino Acid Agents
Excitatory Amino Acid Antagonists
Molecular Mechanisms of Pharmacological Action
Neurotransmitter Agents
Pharmacologic Actions
Physiological Effects of Drugs
Respiratory System Agents
Therapeutic Uses

ClinicalTrials.gov processed this record on April 23, 2015