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

INVESTIGATOR: Barth Wilsey, M.D.

STUDY LOCATION: University of California, Davis

PROJECT TITLE: A Double Blind, Active Placebo Controlled Crossover Trial of the Antinociceptive Effects of Smoked Marijuana on Subjects with Neuropathic Pain; Correlation with Changes in Mood, Cognition, and Psychomotor Performance

PROJECT TYPE: Clinical Study

STATUS: COMPLETE

RESULTS:

Thirty-eight patients with central and peripheral neuropathic pain underwent a standardized procedure for smoking either high-dose (7%), low-dose (3.5%) or placebo cannabis. In addition to the primary outcome of pain intensity, secondary outcome measures included evoked pain using heat-pain threshold, sensitivity to light touch, psychoactive side-effects, and neuropsychological performance. A mixed linear model demonstrated an analgesic response to smoking cannabis. No effect on evoked pain was seen. Psychoactive effects were minimal and well-tolerated, with some acute cognitive effects, particularly with memory, at higher doses.

The full results of this study have been published in the Journal of Pain.

ABSTRACT:

The present study will be designed to evaluate the analgesic effects of inhaled marijuana in patients with neuropathic pain. A within-subject crossover study of the effects of marijuana versus active placebo (lorazepam) on spontaneous and evoked pain will be performed in subjects with complex regional pain syndrome. Spontaneous pain relief will be assessed using VAS scales. Both pain unpleasantness and pain intensity will be assessed to distinguish the effect of marijuana on the motivational-affective aspect of pain relative to the sensory-discriminative component. The degree of pain relief will also be assessed by a seven-point patient global impression of change (PGIC) category scale; i.e., (1) very much improved (2) much improved (3) minimally improved (4) no change (5) minimally worse (6) much worse (7) very much worse. Spontaneous pain relief will also be assessed using the neuropathic pain scale (Galer, 1997) to measure changes in the pain qualities associated with nerve injury pain. If present, areas of mechanical allodynia will be evaluated with repeated testing utilizing a foam paintbrush to determine the degree of the allodynia regression (if any) after smoking marijuana. Evoked pain will be studied using mild to moderately painful heat stimuli delivered to the painful area of the subject's body using the Medoc TSA 2001 quantitative sensory tester (http://www.medoc-web.com/fprod.htm), an electronically controlled Peltier contact thermode. The degree of antinociception in these various chronic pain states will then be compared with neuropsychological effects of marijuana for a correlation synopsis.

The study hypothesis will be that marijuana can induce dose dependent antinociceptive changes in spontaneous and evoked pain in human subjects with nerve injury pain. The second hypothesis will be that higher doses of inhaled marijuana induce greater degrees of antinociception that are not independent of differences in mood, cognition and psychomotor performance. It is furthermore hypothesized that a significantly higher number of neuropathic pain patients receiving "high doses" of marijuana (as compared to those receiving "low doses" or placebo) will not be able to tolerate the side effects. Finally, it is hypothesized that an interaction with time will occur such that antinociception will outlast changes in mood, cognitive impairment and psychomotor performance.

PUBLICATIONS:

Type:

Title:

Journal Article Wilsey B, Marcotte T, Tsodikov A, Millman J, Bentley H, Gouaux B, Fishman S. (2008) A Randomized, Placebo-Controlled, Crossover Trial of Cannabis Cigarettes in Neuropathic Pain. J Pain. 2008 Jun;9(6):506-21. doi: 10.1016/j.jpain.2007.12.010. Epub 2008 Apr 10.

Register for the CMCR Symposium - October 18

On Friday, October 18, 2019 the Center for Medicinal Cannabis Research (CMCR) is hosting a one-day symposium celebrating the pioneers and exploring the progress, promise, and challenges of medicinal cannabis research. Click here for the agenda and further details.

 

The symposium is a free one-day event, but REGISTRATION IS REQUIRED.

 

To register, CLICK HERE

8:00 AM – 5:00 PM

Breakfast at 7:30 AM, lunch included

Location:  UC San Diego's Atkinson Hall, San Diego, California


 

San Diego schools look to take mystery and misinformation out of medical marijuana

Jared Aarons, ABC 10News San Diego, September 10, 2019

Starting this fall, the Pacific College of Oriental Medicine is offering the first-ever certificate program specializing in medical marijuana.

The three-semester class promises to teach health care professionals the basics of medical cannabis, so they can begin to use it in their practice.

"We thought it was important for health care professionals to have objective information about medical marijuana," says school President Jack Miller.

Miller says part of the program's purpose is to help dispel some of the myths surrounding medical marijuana.

Read the rest of the story here


CMCR announces $3M in new research grants to California investigators

The Center for Medicinal Cannabis Research (CMCR) at UC San Diego has been a leader in medical marijuana research since 2000. In the past CMCR has allocated funds to investigators in California to conduct some of the first proof of principle clinical trials of cannabis in neuropathic pain and multiple sclerosis.

With the recent allocation of new funding to CMCR as part of Proposition 64, the CMCR has launched a new wave of grant applications aimed at examining both the efficacy and safety of medicinal cannabinoids. CMCR issued a call for applications to investigators in California in April 2019, received 66 letters of intent from 19 California institutions, and invited 26 applications for primary and pilot studies. Based on external peer review, advice of the CMCR’s National Advisory Council, and rating of attentiveness to CMCR priorities, the Center has selected 5 studies for funding this year. The studies to be funded are listed in the table below.

Study title Principal Investigator
Full funding amount
Effects of Cannabidiol (CBD) versus Placebo as an Adjunct to Treatment in Early Psychosis: Understanding the Mechanism and Mediators of Action Kristin Cadenhead, MD (UC San Diego)  $825,000 
Therapeutic Response of Cannabidiol in Rheumatoid Arthritis Veena Ranganath, MD (UCLA)  $825,000
Cannabidiol for Sedative/Hypnotic-sparing Management of Insomnia in Adults Mariana Cherner, PhD (UC San Diego)  $825,000
Cannabidiol as a Strategy to Treat Alcohol Dependence Giordano de Guglielmo, PhD (UC San Diego)  $300,000
The Role of Cannabidiol (CBD) in Regulating Meal Time Anxiety in Anorexia Nervosa: Safety, Tolerability and Pharmacokinetics Emily Gray, MD (UC San Diego)  $300,000

CMCR anticipates issuing a new call for applications in 2020.

Congratulations to the new CMCR Investigators!

- Igor Grant, MD, Director


The CBD Expert Series: Q&A with a National Leader in Cannabis Research

Nick Musica, CBD Oil Review, August 21, 2019

Recently, Nick Musica of CBD Oil Review had the privilege of speaking with one of the most influential figures in cannabis research, Dr. Igor Grant. Dr. Grant is the Director of the Center for Medicinal Cannabis Research (CMCR) at the University of California, San Diego, as well as a Distinguished Professor in the Department of Psychiatry.

Current CMCR studies are examining the effects of cannabis, and cannabidiol (CBD) specifically, on conditions like autism, psychosis, bipolar disorder, and pain, to name a few.

There is, quite possibly, no one who understands the benefits and effects of CBD better than Dr. Grant. Meet the researcher behind the research.

Read the article here


More News

Click here to access the CMCR news archives.

Igor Grant, MD

Marijuana as Medicine: Can We See Past the Smoke?
North American Cannabis Summit presentation January 2019 (PDF)


Igor Grant, MD

Introduction/Overview
CMCR Symposium, June 2018


Daniele Piomelli, MD, PhD, PharmD

The health impact of cannabis
CMCR Symposium, June 2018


Ziva Cooper, PhD

Therapeutic potential of cannabis for pain alone and as an adjunct to opioids
CMCR Symposium, June 2018


Iain McGregor, PhD

Medicinal cannabis research down under: Introducing the Lambert Initiative for Cannabinoid Therapeutics
CMCR Symposium, June 2018


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