Efficacy of Opioids and Mexiletine for the Treatment of Postamputation Pain

September 29, 2006 updated by: Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)

Randomized, Placebo-Controlled, Double-Blind Cross-Over Trial of Opioids Versus Mexiletine in the Treatment of Postamputation Pain

Persistent pain occurs in 50-85 percent of patients who experience the amputation of an extremity. This study will compare the effectiveness of morphine and mexiletine to placebo in the treatment of postamputation pain.

It is hypothesized that the effects of opioids and mexiletine on behavior and mental functioning in patients with postamputation pain are unlikely to be significant barriers to the clinical use of the drugs.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

The long-term objective of this research is to develop better clinical strategies for alleviating pain resulting from amputation of extremities. Amputation is the most radical form of nerve injury. The two major types of postamputation painful sequela are phantom pain and stump pain. Phantom pain has been defined as painful sensation perceived in the missing body part, or portion thereof (Merskey and Bogduk,1994). Phantom pain is the most distressing, and often difficult to treat, chronic neuropathic pain syndrome that results from direct injury to the peripheral or central nervous system. Recent epidemiological studies indicate that 50-85% of patients experience persistent pain following amputations. This controlled clinical trial will examine the role of opioid analgesics and local anesthetics in the treatment of phantom and associated stump pain resulting from amputations. Specifically, our objectives are to answer the following questions:

  1. Does therapy with opioids and mexiletine result in better management of postamputation pain than treatment with placebo? Using a randomized, blinded, crossover clinical trial, the effectiveness of therapy with the opioid, morphine, and the oral local anesthetic, mexiletine, will be compared with placebo in the management of phantom and associated stump pain following amputations. The effectiveness of the treatment regimens will be judged by improvements in: a) The intensity of ongoing, stimulus-independent pain using established pain intensity and pain relief scales, b) Stimulus-evoked pain using quantitative sensory tests, and c) Impairment of function using established measures.
  2. What are the relative effects of opioids and mexiletine on affective and cognitive function in patients with amputated extremities? Using established tests of neuropsychological function, mood, and psychosocial and physical impairment, affective and cognitive changes associated with the opioid and mexiletine therapies will be quantified and compared with changes associated with placebo treatment. These studies will help determine if the effects of opioids and mexiletine on affect and cognition are likely to limit the usefulness of the medications in the treatment of pain following amputations.

Study Type

Interventional

Enrollment

60

Phase

  • 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
    • Maryland
      • Baltimore, Maryland, United States, 21287
        • Johns Hopkins 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

Ages Eligible for Study

16 years to 83 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

Adults (18 years or older) of both sexes and all races with persistent phantom and or stump pain for 6 months or longer following an amputation will be eligible for enrollment in the study.

Exclusion Criteria:

1) age less than 18 or over 85 years, 2) history of allergic reaction to the study drugs, i.e., morphine and mexiletine, 3) cardiac conduction defects such as second degree or complete heart block, or a myocardial infarction in the last 3 months, 4) severe pulmonary disease, 5) current history of alcohol or substance abuse, 6) seizures, dementia or encephalopathy, 7) pregnancy and nursing mothers, 8) chronic hepatic disease or hepatic failure, 9) hematological disease associated with leukopenia and/or thrombocytopenia, and 10) other terminal illness with a life expectancy of less than 6 months. 11) Finally, to avoid a bias in patient selection, patients who failed to achieve clinically significant pain relief to a previous optimal trial with morphine and/or mexiletine will be excluded. An optimal trial will be defined as minimum of 3 week trial with either agent using a drug titration paradigm where the dose of the drugs were increased at intervals of one week or less.

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: Double

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Pain intensity (0-10 numerical rating scale)

Secondary Outcome Measures

Outcome Measure
Pain relief (0-100%)
Functional activity (Multidimensional Pain Inventory activity and interference subscales

Collaborators and Investigators

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

Sponsor

Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)

Investigators

  • Principal Investigator: Srinivasa N Raja, M.D., Johns Hopkins University

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.

General Publications

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

July 1, 1997

Study Completion

April 1, 2003

Study Registration Dates

First Submitted

September 29, 2006

First Submitted That Met QC Criteria

September 29, 2006

First Posted (Estimate)

October 3, 2006

Study Record Updates

Last Update Posted (Estimate)

October 3, 2006

Last Update Submitted That Met QC Criteria

September 29, 2006

Last Verified

September 1, 2006

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • P01HD033990 (U.S. NIH Grant/Contract)
  • Project 2, P01HD33990

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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