Effects of Smoked Marijuana on Neuropathic Pain

Neuropathic Pain Clinical Trial

Official title:

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

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00254761
• Other study ID #: C02-DA-114
• Status: Completed
• Phase: Phase 1/Phase 2
• First received: November 15, 2005
• Last updated: February 27, 2008
• Start date: November 2003
• Est. completion date: February 2006

Study information

• Verified date: February 2008
• Source: Center for Medicinal Cannabis Research
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Food and Drug Administration
• Study type: Interventional

Clinical Trial Summary

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

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).

Recruitment information / eligibility

• Status: Completed
• Enrollment: 28
• Est. completion date: February 2006
• Est. primary completion date: February 2006
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 18 Years to 70 Years

Eligibility

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 Design

Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Crossover Assignment, Masking: Double Blind (Subject, Investigator, Outcomes Assessor), Primary Purpose: Treatment

Related Conditions & MeSH terms

• Neuralgia
• Neuropathic Pain

Intervention

Drug:
• Cannabis

Locations

Country	Name	City	State
United States	UC Davis Medical Center	Sacramento	California

Sponsors (1)

Lead Sponsor	Collaborator
Center for Medicinal Cannabis Research

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Score on a series of pain scales (heat pain threshold, VAS intensity, VAS unpleasantness, pain relief, neuropathic pain scale).
Secondary	Number of subjects who are unable to tolerate the high dose without significant side effects.
Secondary	Changes in mood, cognitive impairment, and psychomotor performance (mood - VAS happiness, cognition - Digit Symbol Modalities Test, psychomotor performance - Grooved Pegboard Test).

External Links

•   Center For Medicinal Cannabis Research