My poster for the 2014 American College of Clinical Pharmacy Annual Meeting
My abstract for the 2014 American College of Clinical Pharmacy Annual Meeting
Systematic
Literature Review of Randomized Controlled Trials to Evaluate the Efficacy of
Medical Marijuana for Analgesia
Shiny
Parsai, M.S., Pharm.D. Candidate, Ronald A. Herman, Ph.D.; The University of
Iowa College of Pharmacy, Sarah J. Johnson, Pharm.D., BCPS-AQ ID; The
University of Iowa Healthcare
Purpose:
Medical
marijuana has had an evolving and controversial role for the treatment of pain.
This review summarizes and evaluates the current evidence from randomized
controlled trials to examine the efficacy of medical marijuana as an analgesic. Methods:
A
systematic literature review was conducted using PubMed, IDIS, IPA, and CINAHL
databases. Articles were included if
analgesia was a measured outcome in humans, the intervention involved tetrahydrocannabinol (THC) or derivative, was a
randomized controlled trial, and was in English. Two authors did an initial
screen of the abstracts to eliminate irrelevant articles and then a detailed
review of the full text to identify the articles to be included in the evidence
tables. The third author reconciled
differences if there was not a consensus. Data extraction included author name, date, type of pain, sample size, study
design, intervention, efficacy, and adverse effects. Evidence was
organized and analyzed in separate evidence tables by type of intervention: inhaled
cannabis, oral cannabis extracts, dronabinol, THC+CBD spray, and synthetic
analogs. Results:
The initial literature search produced 133 unique
articles. Systematic review of abstracts, yielded 66 for full text review
and 67 were excluded.
Full text review resulted in 48 articles to be included in the evidence tables. Conclusions:
Across each
intervention type at least half of the studies showed a reduction in pain
scores when compared to placebo. There
were 11 of 48 studies that indicated no difference from placebo for analgesia,
with at least one study in each intervention type. There were 6 studies that compared the THC
compound to another analgesic. It was not different from ibuprofen in one study,
diphenhydramine in another study, and it was equivalent to codeine in two
studies. It was inferior to
dihydrocodeine and to morphine in separate studies. Adverse events were a concern in some of the studies.
