Effects of Smoked Marijuana on Neuropathic Pain

February 27, 2008 updated by: Center for Medicinal Cannabis Research

A Double Blind, Active Placebo Controlled Crossover Trial of the Antinociceptive Effect of Smoked Marijuana on Subjects With Neuropathic Pain; Correlation With Changes in Mood, Cognition, and Psychomotor Performance

To determine if smoking marijuana will reduce neuropathic pain without causing too much drowsiness or feeling "too dopey".

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

The case for marijuana's medical use for pain is primarily from experimental studies with normal subjects, which have yielded conflicting results. Experimental subjects have been shown to have significant dose-dependant antinociception effect that is not reversed by opioid antagonism. In contrast to this positive antinociceptive effect, other experiments demonstrated hyperalgesic activity and probably enhancement of the perception of pain upon acute exposure in chronic users of marijuana.

In addition to studying spontaneous pain antinociception, it would be useful to evaluate the response to marijuana following evoked pain. Such evoked pain is produced by stimulation of the skin that is normally not noxious.

Because of the potential side effects of marijuana administration, one of the aims of the present study is to analyze inter-individual variability and the occurrence of dose-dependant analgesia of marijuana with an eye on defining tolerable dosing in clinical neuropathic pain syndromes.

Comparisons: Neuropathic and experimentally induced pain scores will be compared after the administration of escalating doses of low, high, and placebo marijuana cigarettes as provided by the National Institutes on Drug Abuse (NIDA).

Study Type

Interventional

Enrollment (Actual)

28

Phase

  • Phase 2
  • Phase 1

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
    • California
      • Sacramento, California, United States, 95817
        • UC Davis Medical Center

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 68 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Able to understand English
  • Age greater than 18 and less than 70
  • VAS greater than 3/10
  • History of previous marijuana use (i.e., avoidance of marijuana naive subjects)
  • Negative urine drug screening test
  • Nerve Injury a.k.a. Complex Regional Pain Syndrome Type II OR
  • Complex Regional Pain Syndrome Type I OR
  • Neuropathic pain due to confirmed bilateral distal peripheral neuropathy associated with Diabetes I or II, focal nerve injury, postherpetic neuralgia, spinal cord injury with incomplete myelopathy, central pain following a stroke or focal brain lesion, or clinical definite multiple sclerosis of at least 3 months duration.

Exclusion Criteria:

  • Presence of another painful condition of greater severity than the neuropathic pain condition which is being studied
  • Unstable Type 1 or 2 diabetes defined as blood glucose more than 156 mg/dl
  • For diabetic subjects maintained on insulin with a stable blood glucose more than 156 mg/dl, a hemoglobin A1C level of more than 0.11 (normal range, 0.048-0.067)
  • History of traumatic brain injury
  • History of schizophrenia or a past or current history of a serious psychiatric disorder that is currently not well controlled with medications
  • Uncontrolled medical condition - coronary artery disease, hypertension, cerebrovascular disease, asthma, TB, COPD, opportunistic infection, malignancy requiring active treatment
  • Active substance abuse (alcohol or injection drugs)
  • Current use of marijuana (within 30 days of randomization) as determined by urine screening

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: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: 1
High dose cannabis (7.5% THC by weight)
Drug: Cannabis
Experimental: 2
Low dose cannabis (3.5% THC by weight)
Drug: Cannabis
Placebo Comparator: 3
Placebo cannabis
Drug: Cannabis

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Score on a series of pain scales (heat pain threshold, VAS intensity, VAS unpleasantness, pain relief, neuropathic pain scale).

Secondary Outcome Measures

Outcome Measure
Number of subjects who are unable to tolerate the high dose without significant side effects.
Changes in mood, cognitive impairment, and psychomotor performance (mood - VAS happiness, cognition - Digit Symbol Modalities Test, psychomotor performance - Grooved Pegboard Test).

Collaborators and Investigators

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

Sponsor

Center for Medicinal Cannabis Research

Investigators

  • Principal Investigator: Barth L Wilsey, M.D., University of California, Davis

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

November 1, 2003

Primary Completion (Actual)

February 1, 2006

Study Completion (Actual)

February 1, 2006

Study Registration Dates

First Submitted

November 15, 2005

First Submitted That Met QC Criteria

November 15, 2005

First Posted (Estimate)

November 17, 2005

Study Record Updates

Last Update Posted (Estimate)

February 28, 2008

Last Update Submitted That Met QC Criteria

February 27, 2008

Last Verified

February 1, 2008

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • C02-DA-114

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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