Clinical Neuropharmacology of Pain in Spinal Cord Injury- Dextromethorphan Dose Response Clinical Trial

November 20, 2025 updated by: Christine N. Sang, MD, MPH, Brigham and Women's Hospital
This randomized, placebo-controlled, double-blind 4x4 crossover clinical trial was part of a larger NIH-funded study to evaluate the analgesic efficacy of three doses of chronic oral (PO) dextromethorphan compared to placebo in central neuropathic pain following spinal cord injury. Subjects' maximally tolerated doses (MTD) were first determined to establish individual dose-analgesic response relationships in a run-in period; following a washout period, subjects were then randomized to receive an order of four doses of dextromethorphan (including placebo) in a 4x4 Latin square cross-over design.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
26

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Massachusetts
      • Boston, Massachusetts, United States, 02115
        • Translational Pain Research, Brigham and Women's Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years to 70 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Healthy male or female adults, age 18 to 70 with central neuropathic pain for a minimum of 3 months following SCI as confirmed by neurologic evaluation, with an average pain intensity score of at least moderate over at least 50% of the day for the 7 days prior to the screening visit and over the 7 days prior to starting study medication.
  2. Subjects used no medication or a stabilized medication regimen for chronic and well-controlled medical conditions

  3. Serum laboratory examination obtained at study entry:

    • Liver function tests (albumin within 20% of normal, SGOT/SGPT within 50% of normal).
    • For women of childbearing age: negative serum beta HCG.
  4. Postmenopausal women, or be physically incapable of childbearing, or be practicing an acceptable method of birth control.
  5. Normal cognitive function.
  6. Normal communicative ability (English).
  7. Ability to demonstrate competence in recording five times daily in pain diary for 1 week (with 100% compliance), and in completing required questionnaires.
  8. Signed informed consent.

Exclusion Criteria:

  1. Pregnancy or breast-feeding.
  2. Renal or hepatic dysfunction.
  3. Significant cardiac disease (e.g. MI within 1 year).
  4. Signs or symptoms of central neurological disorder, excluding SCI.
  5. Severe psychological disorder requiring treatment.
  6. Concurrent use of monoamine oxidase inhibitors within 2 weeks prior to study entry.
  7. Use of known CYP2D6 (but not CYP3A4) inhibitors or inducers.
  8. History of hypersensitivity or intolerance to dextromethorphan or lidocaine.
  9. Chronic substance abuse, including alcohol.
  10. Participation in a study of an investigational drug or device within 30 days prior to screening for this study.
  11. Poor metabolizer of P450 2D6 substrates.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Placebo Comparator: 0% MTD Dex
0% MTD Dextromethorphan
Drug: Dextromethorphan
0, 25, 50 and 100% of maximum tolerated dose, each administered over a 4 week period
Experimental: 25% MTD Dex
25% MTD Dextromethorphan
Drug: Dextromethorphan
0, 25, 50 and 100% of maximum tolerated dose, each administered over a 4 week period
Experimental: 50% MTD Dex
50% MTD Dextromethorphan
Drug: Dextromethorphan
0, 25, 50 and 100% of maximum tolerated dose, each administered over a 4 week period
Experimental: 100% MTD Dex
100% MTD Dextromethorphan
Drug: Dextromethorphan
0, 25, 50 and 100% of maximum tolerated dose, each administered over a 4 week period

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Mean Pain Intensity (Percent Change From Baseline)
Time Frame: 1st week of maintenance period (week prior to hospital admission for nested study; subjects traveled to Boston on days 6-7 of the maintenance period)
Primary outcome was percent change from baseline in mean pain intensity (transformed Gracely Scale; 0-35). Baseline was defined as the week prior to randomization. The greater the percent change, the bigger the reduction in pain intensity.
1st week of maintenance period (week prior to hospital admission for nested study; subjects traveled to Boston on days 6-7 of the maintenance period)

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Satisfaction
Time Frame: Last week prior to admission (end of 1-week maintenance period)
Satisfaction with study treatment assessed over the 7 days prior to admission (5-point categorical scale)
Last week prior to admission (end of 1-week maintenance period)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Brigham and Women's Hospital

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
National Institute of Neurological Disorders and Stroke (NINDS)

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Christine N. Sang, MD, MPH, Translational Pain Research, Brigham and Women's Hospital (Disclosure: Patent)

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
April 1, 2003

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
January 1, 2008

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
January 1, 2008

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
September 15, 2011

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 16, 2011

First Posted (Estimated)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
September 19, 2011

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
December 8, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 20, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
November 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 2000p001387-A
  • R01NS041503 (U.S. NIH Grant/Contract)

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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