Drug Watch International
MARIJUANA
RESEARCH REVIEW
| A publication of Drug Watch Oregon | Volume 4, No. 4, February 1998 |
A
British review of cannabis
P.
Robson, in the Archives of
Disease in Childhood 1997, provides an interesting review of cannabis from
the perspective of the United Kingdom, addressing the historical and current
medicinal properties of cannabis, the isolation, and synthesization and use of
cannabinoids, as well as an opinion on the consequences of cannabis use.
Addressing its therapeutic
potential, Dr. Robson notes that the usefulness of the synthetic THC analog, nab/lone,
the only one legally available in the United Kingdom, is limited due to
its undesirable side effects. In the 1970's and 80's nab/lone
compared favorably to other antiemetics of the day, but no studies have
compared it to the many antiemetics currently available. Robson noted a 1995
study, which indicated usefulness of the non-psychoactive delta-8 THC as an
effective antiemetic for pediatric cancer patients (Life
Sciences 1995;56:2097-2102). As for the role of nab/lone in the treatment of other medical conditions, Robson points
out that the studies in multiple sclerosis have been conflicting and that a
role for this analogue in glaucoma and pain management has yet to be explored.
He noted that there may be a role for the use of nab/lone in the management of various symptoms of AIDS, and
suggested that further research should be done in this area.
Dr. Robson reviews the adverse
effects of cannabis use including the well-documented impairment of attention,
memory, and psychomotor impairment, leading to risk of accidents on roads or
elsewhere. The psychotic symptoms in vulnerable patients and the chance of low
birth weight infants are also described.
He quotes from the work of others, stating that the risks of long-term
heavy use remain uncertain, but probably include respiratory diseases
associated with smoking and the development of a cannabis dependency syndrome.
The final portion of Robson's paper focuses on the legalization debate.
Comment:
Unfortunately,
this short overview mixes scientifically substantiated facts with opinions of
the author. However, the review gives some useful information on the use of
the THC analogue nabilone, which
should not be confused with dronabinol (Δ9-THC).
When the author refers to any medical efficacy for cannabis, he is referring
to some form of synthesized THC, not smoked plant material. The lack of data
supporting medical benefit from smoked cannabis is
Review
of medical research on Dronabinol (Delta 9-THC)
and marijuana
Citing current interest by the
public and the media in self-medicating with crude marijuana for a variety of
medical conditions, Voth and Schwartz, both physicians associated with the
International Drug Strategy Institute, reviewed the past 20-plus years of
scientific literature on both marijuana and its major psychoactive ingredient,
Δ9-THC. Emphasis was placed on studies addressing cancer chemotherapy,
glaucoma, stimulation of appetite, and spinal cord spasticity.
A search of the scientific
literature located nearly 300 relevant studies, excluding editorials, opinion
statements, abstracts and studies not done in humans. No recent clinical
trials on the use of crude marijuana on human subjects were located other than
for its anti-nausea properties. Toxic or negative effects of exposure and
mitigating circumstances were examined as was the general history of the use
of marijuana in a medical setting. Additionally, a number of the ongoing
efforts to reclassify smoked marijuana from a Schedule I drug to a Schedule II
drug (one that could be legally prescribed) were examined. The authors
concluded that THC, not smoked marijuana, while toxic, has useful therapeutic
benefits, but suggested development of new delivery systems such as nasal
inhalers and suppositories. They concluded that smoking crude marijuana for
medicinal purposes is inappropriate, noting that it "does not qualify as
a medicine and remains a Schedule I drug." (Annals
of Internal Medicine Vol.126; No.10, 15
May1997)
Comment:
This
comprehensive study will be extremely helpful to anyone interested in a brief
but concise overview and discussion of the scientific literature relating to
the debate over whether or not smoking crude marijuana is safe and effective
for therapeutic use. ##
Editorial
review of impact of cannabis use on mental health
In the British Journal of Psychiatry 1997; 171:107-108) Australian
researchers, Hall W, and Solowij N., of the University of New South Wales,
address the effects of cannabis use on behavior. They rely heavily on their
earlier review (Hall et al, Health and
Psychological Consequences of Cannabis Use, done in 1994) The editorial
discusses the reality of cannabis dependence, the adverse effects of cannabis
use on adolescent development and its association with involvement in other
illicit drugs, the scope of cognitive impairment in chronic marijuana users, and
the impact of marijuana use on psychosis and those predisposed to schizophrenia.
The authors conclude that "there is sufficient evidence to say that the
effects of cannabis are neither as benign as its proponents argue, nor as
malignant as individuals on the other side of the debate claim."
Comment:
The
conclusion of the authors seems somewhat at odds with the general adversities
associated with marijuana use as delineated in their editorial. It should be
kept in mind that the only reason for cannabis use by the vast majority of users
is for the express purpose of obtaining its psychoactive properties. Current
arguments for use of crude marijuana in a medical setting, must be put in
context of the long-term impact on the mental health of a particularly
vulnerable age group of individuals. Until acceptable synthetic cannabis
compounds without the psychoactive ingredients of crude marijuana are developed
and tested for their superiority to currently available pharmacologic agents,
use of marijuana in any setting should be avoided. ##
Study
examines impact on tracheobronchial health of habitual smokers of "crack,"
marijuana and/or tobacco
The purpose of this study was
to determine the effects of smoking cocaine, marijuana, and tobacco, either
alone or in combination, on the trachea, larynx and bronchial tube lining. A
secondary purpose was to determine whether the effects of smoking two or more of
these substances at the same time were additive. The study group included 241
smokers and non-smokers from the Los Angeles area. After screening the patients
carefully with routine lung function tests, all the subjects underwent a
bronchoscopy examination with biopsies of the lining tissue of the trachea and
bronchial tubes. Smokers of the illicit substances and tobacco all exhibited
frequent abnormalities in bronchial linings. Patients smoking all three
substances did not show more frequent abnormalities than those smoking both
cocaine and tobacco or marijuana and tobacco. The effects of marijuana and
tobacco appeared additive while cocaine, when smoked alone, led to the fewest
abnormalities.
Some changes were similar to
abnormalities seen in bronchitis, while other changes were pre-malignant in
nature. (Fligiel SEC, Roth MD, Kleerup EC, et al., Chest 1997 112:319-326.)
Comment:
The
authors note that "despite the growing evidence that smoking is hazardous
to health" the practice of smoking, whether of tobacco, marijuana, and/or
cocaine, "continues to attract new users." The smoking status of the
participants in the study was based on self-reporting, which suggests using
caution in interpreting the results. However, the researchers were quite careful
in analyzing the data from the study, which indicated that the negative effects,
using various combinations of marijuana, cocaine, and tobacco, is additive,
increasing the risk for long-term lung complications. The results of this study
further indicate that smoking would be a very poor vehicle for delivery of any
medicinal substance. ##
Profuse
bleeding results from marijuana smoker's experiment
A 17-year-old boy was
hospitalized with bleeding from his mouth and skin. Blood tests suggested
anticoagulant therapy of some kind. Despite the boy's denial, his family found a
potent rodent killer, Brodifacoum, which is 100 times more toxic than Coumadin,
a prescription drug used for blood thinning. After medical and psychiatric
treatment over the next six months, the patient admitted he learned to smoke
marijuana laced with rodent poison from friends at a party. Despite his severe
bleeding he was admitted again 18 months later for bleeding from his nose, mouth
and both kidneys. He denied smoking rodent killer with marijuana, but changed
his story later when confronted with the severe coagulation defect. Reported by
LaRosa et al, Arch Pathol Lab Med 121:67-69,1997.
Comment: Bizarre behavior while consuming marijuana is not unusual. However, the combination of rodent killer and marijuana taken by smoking is unique. All other 18 reports in the literature of Brodifacoum ingestion were accidental ingestions in children. The subsequent medical care cost (using conservative estimates for days of hospitalization) for this behavior was well over $150,000. ##
------------------------
Material used in this
publication has been reviewed and commented on by William M. Bennett, M.D.,
Professor of Medicine, Division of Nephrology, Clinical Pharmacology and
Hypertension at Oregon Health Sciences University, Portland, Oregon
Drug
Watch Oregon
P.O. Box 5853, Portland, Oregon
97228-5853
Phone/Fax: 360-263-3964
Email address: MJRRview@aol.com
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