Voters in six states will be weighing in on the issue of
decriminalizing medical marijuana, which has come under stepped-up
prosecution on the federal level in recent years. Here’s the latest
science on the pros and cons of its use for a variety of health
indications.
"The basic concept of using medical marijuana for the same
purposes and with the same controls as other drugs prescribed by
doctors, I think that’s entirely appropriate."
Barack Obama, 2008
At a time when six states are holding referendums on marijuana,* it
seems important to get a clearer understanding of what Barack Obama
meant by "the same controls." Truthout spoke with Steph Sherer,
executive director of Americans for Safe Access (ASA), the nation’s
largest organization of scientists, physicians and patients who advocate
for the decriminalization of medical marijuana. This is just a taste of
what Barack apparently meant:
- During the 31/2 years of the Obama administration, the Drug
Enforcement Administration (DEA), an arm of the Department of Justice
(DOJ), conducted more raids on state-licensed dispensaries than the Bush
administration did in eight years. The DEA hit more than 200
dispensaries, confiscated the marijuana and left a trail of wreckage in
their wake. A dozen proprietors are in prison and nearly 100 more are
awaiting prosecution; - The most effective method the DEA employs, is to write a menacing
letter to the landlord who owns the building where the dispensary
operates, threatening him with closure even though the building is up to
code: This has resulted in a further 400 closures at least; - The DEA also has been obstructing scientific research into
marijuana. Brad Burge, an executive officer with the Multidisciplinary
Association for Psychedelic Studies (MAPS), told me how. For the past 11
years, MAPS, in collaboration with botanist/soil scientist Lyle Craker,
PhD, of the University of Massachusetts, has sought to obtain a permit
from the DEA to grow marijuana for research purposes: The DEA has
consistently turned down their application with one excuse or another.
Finally MAPS got fed up and is seeking relief in the First Circuit Court
of Appeals. It’s worth a mention that MAPS is not an aging-hippie
commune, but rather a major foundation that bankrolls medical and
psychiatric research, here and abroad, by top scientists with an
interest in hallucinogenic drugs and marijuana; - Had he wished to do so, Obama could have deftly reined in the DEA,
for the term of its Bush-appointed administrator, Michelle Leonhart,
was slated to expire around the time of his inauguration. Instead of
replacing her, Obama appointed her to another full term in office; - The IRS has gotten into the act by harassing dispensary owners on
the basis that they did not pay enough income tax, even though in almost
every instance the proprietors did in fact pay the requisite amount of
tax; - The Federal Deposit Insurance Corporation, though not an arm of the
White House, is governed by the President and by Congress. It has
squeezed Citigroup, Wells Fargo and Bank of America, along with credit
card companies, to deny services to medical marijuana businesses that
are legal under state law. According to ASA, no large bank in Colorado
will service legal medical marijuana businesses; - The National Institute on Drug Abuse (NIDA) has begun obstructing
research by denying marijuana to scientists. Thus, Sue Sisley, MD, a
psychiatrist and internist at the University of Arizona, sought to
conduct a trial of marijuana for treating Post-Traumatic Stress Disorder
(PTSD), a condition that is severely refractory to currently-used
medications. Her PTSD study was approved by the US Food and Drug
Administration (FDA); all she needed was the weed, which NIDA grows from
11-year-old crops. NIDA declined her request and sent her a ten-page
trashing of the very protocol the drug experts at the FDA had approved;
at this writing her important study is in limbo.
To Steph Sherer, the most outrageous maneuver by the DOJ is the "Cole Memo."
This document was sent to all US Attorneys across the country,
threatening governors as well as state and local officials with
punishment under federal law, which bans marijuana, if they signed a
medical marijuana decriminalization bill into law.
Whatever the outcome of the election for the president, 2012 is
likely to be a red-letter year for marijuana activists. Five states –
Arkansas, Colorado, Massachusetts, Oregon and Washington – are holding
referendums that would, to some degree, legalize marijuana. The latest polls show that the referendums in Colorado,
Massachusetts, and Washington State are likely to succeed. Montana’s
Referendum 124, which seeks to tighten controls on marijuana, is likely
to go down in flames. Arkansas’
legalization seems dicey, while Oregon’s proposition trails narrowly,
but the remarkable fact about the polling data is that it cuts across
the red/blue divide.
With the US public in general favors decriminalizing marijuana,
and propositions to that effect on state ballots, could it be that
marijuana is more dangerous than we had heretofore thought, and the Feds
are protecting our health?
No. The single best source on the indications and side effects of
medical marijuana was published in 2010 by Health Canada, the equivalent
of our FDA (Information for Health Care Professionals:
Marijuana). Since that date, new indications have come under study, but
nothing gruesome has emerged to warrant Obama’s war on marijuana. As in
any hot field of science, some indications will hold up, while others
will turn out to be false leads. New side effects may emerge, but
marijuana has been around for so many centuries that it probably holds
few unwelcome surprises for us. But there was a surprise of an opposite
nature from a team at Yale,
which found alcohol’s "gateway" effect – its proclivity to lead to
addiction to some other drug – to opiates is much greater than
marijuana; if you abuse alcohol you are much more likely subsequently to
abuse opiates. This is one more data point that belies the myth that
"reefer madness" leads to opiate addiction.
Marijuana has been tried for many indications, among them pain,
anorexia nervosa, multiple sclerosis, Parkinson’s disease and bladder
dysfunction. Three indications that are acceptably well-studied, solid
and frequent – for which there exists an adequate body of data to draw
inferences, bearing in mind that subsequent clinical trials could knock
this preliminary work right out of the water – are described below.
Preliminary Considerations
I use the word "marijuana" where some authors prefer "cannabis": In
plain English, a joint of dried leaves. When I use the term "THC," I
mean a capsule containing a measured amount of only one chemical,
delta-9-tetrahydrocannabinol. The chemicals comprising the
pharmacologically interesting components of the leaf are called
cannabinoids, and with the exception of THC are identified as CBC, CBD,
CBG and so forth.
There are two major ways of delivering cannabinoids. Naturalistic
experiments seek to replicate the real-life use of marijuana as closely
as possible, in which case the subjects or patients puff on a joint. The
advantage of this method is that the subject gets the full dose of
cannabinoids across the lung alveoli and into the bloodstream. The
disadvantage is that the investigator does not know for sure which
cannabinoid or combination is responsible for the pharmacological
effect, although he can be reasonably sure that it is predominantly THC.
Standardized cigarettes are available with a fixed amount of THC, but
smokers can circumvent this to a certain extent by the depth and
frequency of inhalations. THC capsules solve this problem, but raise
another: The full amount of THC is not absorbed from the gut. Both
complications can be gotten around by measuring plasma levels.
A matter of concern is that the smoked marijuana leaf contains many
of the same carcinogens as ordinary cigarettes. Of course, this is not
an issue in research studies, but until the matter of carcinogenicity is
settled, users of marijuana would do better to ingest it in tea or
brownies.
Nausea and Vomiting
The most widely known indication for marijuana is the control of
nausea and vomiting in cancer patients undergoing chemotherapy and/or
radiation.
Anti-cancer drugs work by killing off rapidly-dividing cells, which
include, but are not confined to, cancer cells; the cells of the
gastrointestinal tract "turn over" very rapidly, making them unwanted
targets of chemotherapeutic agents. Radiation also rakes the gut raw,
causing nausea and vomiting. Drugs that suppress nausea and vomiting are
called anti-emetics, and there are a number of such drugs on the
market, of which Compazine may be the most familiar, though not the most
effective. Over the years, however, mounting anecdotal accounts attest
to the effectiveness of smoking of marijuana for suppressing nausea and
vomiting. This indication for marijuana is so well known that we need
not belabor the point, though today marijuana is usually administered in
capsules containing THC – the principal active ingredient, in a dose
range of 5 mg to 20 mg daily in divided doses.
Less familiar are the uses of marijuana to ameliorate the wasting
syndrome and loss of appetite in AIDS and cancer patients. Anorexia –
loss of appetite – is one of the more difficult-to-manage complications
of cancer, because many cancer patients simply do not want to eat. Some
patients do benefit, in doses of 2.5 mg to 5 mg of THC three times a
day, but a comparative trial of THC versus megestrol acetate [Mantovani G
et al: Oncologist 2010;15:200-211] found the latter drug to be superior
in both appetite stimulation and weight gain. The picture is somewhat
brighter for anorexia and weight loss in AIDS patients: Oral THC
(Marinol) is approved for AIDS-related weight loss in Canada, and
several studies, including one large one [1], have found it effective in anorexia.
Anorexia nervosa is an eating disorder which has been little studied
for marijuana’s efficacy either in the smoked or THC form. The available
evidence is disappointing; one would expect that a drug which causes
the "munchies" would benefit patients with anorexia nervosa, but such is
not the case. Possibly anorexia from cancer and AIDS on the one hand,
and anorexia nervosa on the other, are driven by different
neuropsychological mechanisms. Anorexia nervosa is marked by a
misperception of body image; the patient thinks she is too fat even when
she is wasting away. AIDS and cancer patients do not evince such a
misperception.
Cancer Pain
In Canada, Sativex (a compound of cannabinoids), is approved as an
adjunct to opiate analgesics for adults with moderate to severe,
advanced cancer pain in clinical situations where even the highest
tolerated dose of opiates is inadequate. Is THC alone adequate for
cancer pain?
One placebo-controlled study found that 15mg and 20mg, but not 5mg
and10mg, of THC delivered significant relief from moderate to severe
pain from advanced cancer. However, the patients could not tolerate the
higher dose owing to over-sedation and confusion. One wonders, however,
if the attending physicians might not welcome over-sedation if it were
they who were dying of cancer.
Controlled studies compared THC with opiates. In one study, the
opiate was 60 mg to 120 mg of codeine against 10 mg and 20 mg of THC.
Aside from over-sedation – difficulty walking and blurred vision – 20 mg
THC caused severe anxiety. Though the higher dose of THC was comparable
to codeine for analgesia, it was not deemed useful owing to its side
effects.
THC clearly has a place in the management of cancer pain, but on the
basis of limited data, opiates are probably superior analgesics. It is
probably useful as an adjunctive agent. Marijuana has been found to
augment the analgesic effects of morphine and oxycodone without altering
opiate plasma levels; the implication is that opiates might be given in
lower doses, with fewer side effects, but the same degree of analgesia.
This hypothesis remains to be tested. In the meantime, patients in pain
should not be deprived of therapeutically adequate doses of opiates;
pain is not a moral issue.
Non-Cancer Pain
Two types of common non-cancer pain for which the evidence is either
adequate, compelling or promising are described below. Other types of
pain, i.e., post-operative, had to be left out because of inadequate or
inconclusive studies.
Arthritis
Rheumatologists (specialists in joint diseases) recognize three types of arthritis:
- Osteoarthritis, a degenerative disease caused by the breakdown of
the "padding" cartilage between bones. It is the most common form of
arthritis; the rubbing of bone against bone causes pain and
inflammation. Marijuana has both analgesic and anti-inflammatory
effects, so it is not surprising that it is reported to be effective for
symptomatic relief of osteoarthritis - Rheumatoid Arthritis (RA), less common than osteoarthritis, is an
autoimmune disease (the organism produces antibodies that attack its own
tissues). A good controlled trial using Sativex, led the authors of
Health Canada to conclude that "the results indicated a therapeutic
potential for cannabinoids in RA and further research was suggested." - Juvenile Arthritis. Few physicians would be likely to advocate the
use of marijuana in children at the present time because scientists do
not know the effects of the drug on development, However, older teens
could probably use the drug safely.
Multiple Sclerosis
Multiple sclerosis
(MS) is one of the most heartening indications for marijuana. The
disease, which is irreversible, is marked by the patchy degeneration of
the myelin sheath that surrounds nerve fibers. Myelin serves the purpose
of an insulator that ensures the orderly dispersion of electrical
signals in the brain. When the sheath begins to deteriorate, the
electrical activity is no longer confined to discrete pathways; it goes
wild and the patient starts to experience neurological and psychiatric
symptoms, among them painful spasticity, muscle weakness, visual
disturbances and depression. As the disease progresses, the patient
becomes increasingly disabled and may end up in a wheelchair. People
with MS have about the same life expectancy as the general population,
but the quality of life can be ghastly. In other cases, however, the
disease is mild and sufferers can hope to lead a reasonably normal life
Fortunately, the pharmaceutical industry has developed powerful new
drugs to treat the symptoms and arrest the progression of MS.
Corticosteroids are effective for treating acute flare-ups of the
illness. Interferons slow the course of the disease. Copaxone injections
block the immune system’s assault on the myelin sheath, thereby
preventing further degeneration. Other effective, specific drugs have
hit the market in the past few years. And older drugs are available for
treating specific symptoms such as bladder incontinence and depression.
Yet two recent Canadian surveys [2]
found that, depending on the province, a third to nearly a half of MS
sufferers had either experimented with marijuana or used it regularly
for relief of pain and spasms. MS may be an instance where the patients
are ahead of the scientists: Two large clinical trials [3]
sought to assess the efficacy of smoked marijuana for pain and spasms.
Outcome was measured by patient reports and by a rating scale called the
Ashworth Scale. In both studies, the patients reported significant
relief that could not be measured on the neurologists’ Ashworth Scale;
it is now believed that the Scale may be defective and that the patients
just might be correct. While the scientists dither over this one, MS
continues to be one of the major uses for marijuana. It would not be
surprising if marijuana turned out to exert anti-inflammatory properties
in MS sufferers, as it does in patients with arthritis.
Other Conditions
Candidate Obama was correct: Marijuana is no different from any other
drug, only older, centuries older. But thanks to the hysteria embodied
in movies like "Reefer Madness," little serious research was conducted
until after World War II. As far as the pharmacological community was
concerned, marijuana was a "new" drug (history repeats itself) and like
any new drug with a broad spectrum of action (analgesic,
anti-inflammatory, anti-emetic), marijuana was tried against a plethora
of indications. These include neuropathic pain (that is, pain caused by
damage to the nerve, as in AIDS neuropathy, as distinguished from
pressure on the body’s pain receptors, as caused by malignant tumors), and glaucoma,
for both of which the available evidence is pretty solid.There are
theoretical reasons, namely the presence of receptors for marijuana
alkaloids in muscle tissue, why marijuana might be effective in movement
disorders like Parkinson’s disease. Preliminary studies of various
movement disorders are encouraging but small in scale.
THC dilates the bronchial tubes and decreases bronchospasm, so it has
been tried with some success in asthma, but this indication would not
seem to be a matter of great urgency because there are a number of
excellent anti-asthma drugs on the market. There are also a number of
drugs for treating migraine and cluster headaches, both of which are
often excruciating and refractory to conventional treatments. Curiously,
most of the same drugs are used for migraine and cluster headaches, and
a few case reports or small trials suggest that marijuana is also
effective for both; this would seem to be an area that merits a faster
pace of research.
The foregoing considerations do not exhaust the afflictions against
which marijuana has been tested. Notably absent are psychiatric
indications. Clinical trials for anxiety and depression are
contradictory: Some patients get better, others get worse. Of greater
concern are a number of studies that suggest a link between marijuana
and psychotic ideation and suicidal thoughts or attempts. To confound
matters even further there are data reporting that marijuana has
antipsychotic activity.
One publication of great interest – assuming it can be supported –
found that an evening dose of THC calms the restlessness and mental
agitation of demented, elderly patients. [4]
If supported, it would be a major breakthrough because there is as yet
no safe and effective medication for this patient population. Marijuana
has also been tried with promising results in Alzheimer’s dementia, but
again, the studies are small and require replication before marijuana
can be advocated for these indications, bearing in mind the fragility of
the data in the field of psychiatry.
Side Effects
The most conspicuous side effects of marijuana are related to the
central nervous system (CNS). Although the occasional recreational use
of marijuana is probably harmless, heavy usage – usually smoking – is
associated with disorientation, confusion, depersonalization, and
paranoia. According to the Health Canada paper cited earlier, persons with schizophrenia are at much greater risk to these side effects.
Marijuana exerts a significant effect on thought processes
(cognition). It disrupts memory, attention, concentration and scores on
psychological tests designed to measure cognitive processes. There is no
doubt about the deleterious side effects of marijuana on short-term
cognition, but its long-term effects are more controversial. Further
research on the long-term effects of marijuana is required, but it is
difficult to see how this can be accomplished in the present climate of
re-criminalization by the Obama administration; users of marijuana are
unlikely to come forward for study.
Non-CNS side effects are generally dose-related; moderate
recreational use is unlikely to produce worrisome deleterious effects.
Clinicians are concerned about the use of marijuana by AIDS patients,
because marijuana may suppress the immune system, although the data are
conflicting. More convincingly, studies show that initial use of
marijuana increases the heart rate, but after 8 to10 days the heart rate
fell below normal. Since marijuana exerts numerous effects on the
cardiovascular system, there is some concern that heavy use may
predispose to angina pectoris and heart attacks.
Three studies spanning 20 years and summarized in the Health Canada paper
concur that smoking of marijuana by the mother while pregnant causes
cognitive deficits (attention span, visual analysis, hypothesis testing)
in the adult offspring. Effects on the newborn, on the other hand, are
contradictory.
Marijuana clearly has multiple effects on human sperm, such as a decrease in sperm count. [5] However, infertility has not been demonstrated yet.
A number of studies have demonstrated that the liver is a major
target organ for damage from heavy marijuana usage. Daily smoking of
marijuana for protracted periods of time has been linked to fatty liver
and to fibrosis – the replacement of functional liver tissue by inert
fibrous tissue. Oddly, studies on the effect of marijuana on the course
of Hepatitis C are conflicting, a significant issue which is
counterintuitive to the known damage that marijuana causes to liver
tissue. [6]
Conclusion
There is good evidence for the efficacy of marijuana in cancer and
non-cancer chronic pain, nausea and vomiting from chemotherapeutic
drugs, radiation and multiple sclerosis, as well as promising evidence
for a number of other illnesses. Like every other drug, marijuana has
side effects, but they are comparatively few and confined to heavy
users. Barack Obama was correct in likening marijuana to other
pharmaceutical products, right in promising to end W’s marijuana witch
hunt, and deceitfully wrong in escalating that witch hunt beyond Bush’s
wildest dreams. It is to be hoped that the referendums legalizing
marijuana for medical use pass and the federal persecution of those
using, studying or providing the drug for medical purposes cease.
* The six states holding referendums concerning marijuana include:
Arkansas – Arkansas Medical Marijuana Act of 2012 – Legalizes marijuana for medical indications
Colorado – Amendment 64 – Legalizes possession and growing of small quantities of marijuana
Massachusetts – Question 3 – Legalizes marijuana for medical indications
Montana – Referendum 124 – seeks to restrict availability of marijuana
Oregon – Measure 80 – Would license production and sale of marijuana
Washington State – Initiative 502 – Decriminalizes up to 1 oz for personal use
1.
Beal JE et al: J Pain Symptom. Manage. (1995) 10:89-97
2.
Page SA et al. (2003) Canadian Journal of Neurological Science 30:201-205 and Clark A.J. et al.(2004)neurology.62:2098-2100
3.
Zajicek J et al.: Lancet (2003) 362:1517-1526 and Wade D.T. et al. (2004):Multiple Sclerosis 10:434-441
4.
Walther S et al Psychopharmacology (Berl)2009; 185:524-528
5.
Whan L B et al:(2006) Fertility and Sterility 85:653-660
6.
Fernandez-Rodriguez C M et al.(2004) Liver International 24:477-483
