Analgesic Efficacy of Smoked Cannabis

INVESTIGATOR: Mark Wallace, M.D.

STUDY LOCATION: University of California, San Diego

PROJECT TITLE: Analgesic Efficacy of Smoked Cannabis

PROJECT TYPE: Clinical Study

STATUS: COMPLETE

RESULTS:

In a randomized, double-blinded, placebo controlled, crossover trial in fifteen healthy volunteers, we evaluated the effects of low, medium, and high dose smoked cannabis (respectively 2%, 4%, and 8% 9-delta-tetrahydrocannibinol by weight) on pain and cutaneous hyperalgesia induced by intradermal capsaicin. Capsaicin was injected into opposite forearms 5 and 45 minutes after drug exposure and pain, hyperalgesia, tetrahydrocannibinol plasma levels, and side effects were assessed.

Five minutes after cannabis exposure, there was no effect on capsaicin-induced pain at any dose. By 45 minutes after cannabis exposure, however, there was a significant decrease in capsaicin-induced pain with the medium dose and a significant increase in capsaicin-induced pain with the high dose. There was no effect seen with the low dose nor was there an effect on the area of hyperalgesia at any dose. Significant negative correlations between pain perception and plasma delta-9-tetrahydrocannibinol levels were found after adjusting for the overall dose effects. There was no significant difference in performance on the neuropsychological tests.

This study suggests that there is a window of modest analgesia for smoked cannabis with lower doses decreasing pain and higher doses increasing pain.

The full results of this study were published in the journal Anesthesiology.

ABSTRACT:

By every criteria (deterioration in quality of life; loss of work days, and therapy directed dollars) pain is appreciated to be a major medical problem. Recent findings in the molecular biology and the pharmacology of pain transmission have shed light on mechanisms of nociceptive processing and the activity of a variety of "novel therapeutic" modalities that include the cannabinoids. Although the pre-clinical literature suggests that the cannabinoids produce antinociception and anti-hyperalgesic effects, the efficacy of the cannabinoids in the human pain state is unclear. As an experimental variable, clinical pain is a multidimensional phenomenon with few objective physical correlates. Many other factors such as emotional status and coping skills, make "pain" difficult to study in the clinical setting. An important development has been the implementation of well-controlled experimental pain models to investigate the sensory components of pain processing and to use these models in the assessment of analgesic efficacy in normal volunteers. To the degree that human experimental pain models can predict analgesic efficacy of novel agents, the role of mechanisms defined in preclinical studies can be translated to the human experience under well-controlled conditions. Human experimental pain has been used to test a wide range of currently available analgesics. Knowing the effect of these agents on human experimental pain, I now wish to study the effects of cannabis on human experimental pain and how this compares to commonly used analgesics.

PUBLICATIONS:

Type:

Title:

Journal Article Wallace M, Schulteis G, Atkinson JH, Wolfson T, Lazzaretto D, Bentley H, Gouaux B, Abramson I (November 2007) Dose-dependent Effects of Smoked Cannabis on Capsaicin-induced Pain and Hyperalgesia in Healthy Volunteers. Anesthesiology. 2007 Nov;107(5):785-96.

Inconsistent, inaccurate information hinders medical cannabis’ potential to ‘revolutionize’ health, wellness

Robert Solomon, Healio, October 30, 2019

The full impact of legalizing medicinal cannabis in some parts of the U.S. is hindered by inaccurate, inconsistent information, according to a panelist at the OCTANe Medical Technology Innovation Forum.

Nearly three dozen states have legalized some form of medicinal cannabis. But those laws are not universal in their language, according to Governing.com, a website that covers politics, policy and management. In addition, cannabis is on the Drug Enforcement Administration’s Schedule I list — meaning it has no currently accepted medical use, high potential for abuse and risk for arrest with use.

“We don’t know what we’re really regulating on cannabis at this point,” Robert Solomon, JD, MA, co-chair of the University of California at Irvine’s Center for the Study of Cannabis, told attendees. “We haven’t come to grips with a fact-based analysis” that answers the questions 'What’s our goal? What’s our point?’ So, we have come up with this mish-mash of incentivizing selling but dis-incentivizing growth.”

Read the story here


UC San Diego’s Center for Medicinal Cannabis Research Awards Grants for Five Novel Studies

Scott LaFee, UC San Diego News Center, October 10, 2019

The Center for Medicinal Cannabis Research (CMCR) at University of California San Diego School of Medicine, the nation’s oldest research center for scientific inquiry into the safety and efficacy of cannabis, has announced $3 million in research grants to explore new applications of cannabis for a number of novel medical applications.

The grant funding, to be allocated to five California-based research teams, will be used to study the efficacy and safety of medical cannabis as both a supplementary or alternative treatment for schizophrenia, rheumatoid arthritis, insomnia, alcohol dependence and anxiety linked to anorexia.

Read the rest of the story here


Cannabis Research Buds Out in New Directions, Arthritis to Insomnia

Debra Kamin, This Week at UC San Diego, October 10, 2019

With 33 states and the District of Columbia having legalized medical marijuana, it was inevitable that there would be much talk of its therapeutic benefits, real or imagined. But lost in the equally inevitable hype has been hard scientific proof.

For almost two decades, the Center for Medicinal Cannabis Research (CMCR) at UC San Diego has been conducting such research, for much of that time largely alone and often, given the controversial nature of the subject, with limited resources. But times are changing, and CMCR recently announced a first wave of five new grants worth a total of $3 million to explore the efficacy and safety of medical cannabis as a supplementary or alternative treatment for schizophrenia, rheumatoid arthritis, insomnia, alcohol dependence and anxiety linked to anorexia.

Read the rest of the story here


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


Robert Fitzgerald, Ph.D.

Senate Caucus on International Narcotics Control

(October 23, 2019)


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


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