Medical Marijuana: Miracle Treatment or Abused Drug?

by Georgina Lee, PharmD 2011 | lee@myhousecallmd.com

What do the movies “Pineapple Express,” “Cheech & Chong,” Bob Marley, and the TV series “Weed” all have in common?  The answer is marijuana, also known by its many aliases as Mary Jane, hemp, pot, dope, giggle weed and grass to name a few.  Its popularity dates back as far as the third millennium B.C.  It has been used for recreational, religious, spiritual and medicinal purposes (apparently it’s not just used by experimental college students!).  Marijuana, scientifically known as “Cannabis,” is made up of dried parts of the Cannabis sativa hemp plant including its flowers, stems, leaves and seeds.   The resinous part of the plant (the concentrated secretions the plant produces) is known as hashish or “hash,” which also contains psychoactive properties.  Most people recognize marijuana by its distinct smell when smoked which can be described as a simultaneously sweet and sour odor.  Typically, marijuana is smoked as a cigarette (aka “joint”), in a pipe or is humidified in a bong.  It is also smoked in “blunts,” which are cigars that have been emptied of tobacco and refilled with marijuana (immortalized by countless reggae songs).  Since the blunt retains the tobacco leaf used to wrap the cigar, this type of delivery combines marijuana’s active ingredients with nicotine and other harmful chemicals (a double whammy).  Additionally, people mix marijuana into foods such as the case with “magic brownies.” This form of consumption produces stronger effects than when smoked (it seems like the brownies would taste better too).  The use of Marijuana has long been a source of controversy and debate in regards to its role in the medical world and it’s easy to see why.  As medical marijuana dispensaries continue to spring up on street corners across America, the medical community must take a good hard look at the need for marijuana as part of its arsenal of medicinal therapies.

How does Marijuana affect the brain?

The main active chemical in marijuana is delta-9-tetrahydrocannabinol or THC for short.  THC acts upon cannabinoid receptors in various parts of the brain including the cerebellum.  The cerebellum is responsible for balance, posture and coordination of movement after receiving input from sensory systems and the motor cortex (the area in our brain that controls our voluntary movements).  THC also acts upon the hippocampus which contains many cannabinoid receptors and is involved with memory formation.  Some studies have suggested that marijuana affects memory by decreasing the activity of neurons in this area and, because the hippocampus is involved in new memory formation, someone under the influence of marijuana may have impaired short-term memory (“hmm…what happened last night?”).  However, most studies in humans suggest that if a person stops using marijuana, their memory abilities can recover.  Marijuana also affects sensory perception in the cerebral cortex, which can lead to an altered perception of incoming sensory information (such as finding a sock or your friend’s nose extremely funny).

How is Marijuana used medically?

Marijuana is currently used for the treatment of a number of medical complaints and conditions including nausea, vomiting, lack of appetite, spasms, glaucoma and pain.  In 1992, scientists discovered a naturally produced substance called anandamide that activates THC receptors and has many of the same physiological effects as THC.  The discovery of anandamide led to the discovery of additional cannabinoid molecules and receptors including 2-arachidonoglycerol, which helps to control pain.  Oral forms of THC such as Dronabinol (Marinol) are already available to treat chemotherapy-induced nausea and vomiting in addition to treating weight loss in patients who suffer from AIDS wasting syndrome.  However, some studies have shown that Marinol lacks several of the therapeutic compounds available in natural cannabis (aka Marijuana) that has 66 naturally occurring cannabinoids.  One of these is known as cannabidol (CBD), which is a non-psychoactive cannabinoid that has been clinically demonstrated to have analgesic, anti-spasmodic, anxiolytic, anti-psychotic, anti-nausea and anti-inflammatory properties.  Other researchers found that natural extracts of CBD, when administered with THC, significantly reduced pain and other symptoms in patients suffering from multiple sclerosis (an autoimmune disease that affects the brain and spinal cord).  CBD has also demonstrated neuro-protective properties against glutamate neurotoxicity (which occurs during a stroke), cerebral infarction (localized cell death in the brain) and ethanol-induced neurotoxicity.  Some clinical trials have shown CBD to have anti-tumoral properties (via the inhibition of the growth of glioma (brain tumor) cells and selectively induction apoptosis (programmed cell death) in malignant cells…pretty cool if you ask us).  The other cannabinoids found in Marijuana have demonstrated anticonvulsant, anti-inflammatory, anti-depressant, and antioxidant activity in addition to slowing disease progression in certain autoimmune and neurologic diseases including multiple sclerosis, amyotrophic lateral sclerosis (Lou Gehrig’s disease) and Huntington’s disease.  Keep in mind, however, that some of these trials are in very early stages and more in depth research must take place to draw any concrete conclusions.

Wow this sounds like a great plant.  What’s the hold up?

According to the National Institute on Drug Abuse (NIDA), 25.8 million Americans aged 12 and older had abused Marijuana at least once a year.  The NIDA-funded 2008 Monitoring the Future Study showed that 10.9% of 8th graders, 23.9% of 10th graders, and 32.4% of 12th graders had abused marijuana at least once a year prior to being surveyed.  That’s a lot of young people getting high!

Short-term side effects of Marijuana include cough, increased heart rate, dizziness, silliness (“the giggles”), sleepiness, hunger (better known as the “munchies”), confusion, memory impairment, bloodshot eyes and changes in eating and sleeping habits.  NIDA researchers rank peer pressure and curiosity as the leading reasons for this drug abuse.  They also note that users can become heavily dependent on “pot” as a way to cope with anxiety, anger, depression and boredom because of its relaxing properties.  In one study conducted in Memphis, Tennessee, researchers found that out of 150 reckless drivers, 33% tested positive for marijuana and 12% tested positive for both marijuana and cocaine.  That means 45% of “bad drivers” in Memphis are driving around under the influence of Marijuana!  Many anti-Marijuana ads and commercials have surfaced over the years as a result of these statistics in order to educate and prevent people from abusing the drug.  Long-term concerns about smoking Marijuana include dependency, increased risk of cough, bronchitis and emphysema (a progressive disease of the lung that causes shortness of breath) as well as increased risk of cancer of the head, neck and lungs due to the smoke inhalation (Google Image search “oral cancer” for some exquisite photos to scare your kids straight).  The moral of the story is that Marijuana, when used inappropriately or unnecessarily, can be a very dangerous drug.

Hmm, this sounds like a tricky situation…

Essentially, legalizing medical Marijuana is a tug of war between parents, patients, medical professionals, pro- and anti-activist groups, city and state, state and federal, so on and so forth (you get the idea). Currently, the talk of the town surrounds Marijuana dispensaries and their growing locales around the nation.   Many anti-Marijuana activists want to shut down these dispensaries while owners and pro-Marijuana activists fight to keep them open.  A New York Times article stated in its June 24, 2005 editorial “When Medical Marijuana is Misused” that “Those who believe, as we do, that marijuana should be legally available for medical treatments have to be concerned about abuses in California’s pioneering medical marijuana program.  If the abuses cannot be curbed, a political backlash could undermine the ability of thousands of patients to get marijuana to treat the nausea of chemotherapy, loss of appetite that accompanies AIDS and other medical problems…Public officials would be wise to clean up their programs lest flagrant abuses by a few bad actors bring about destruction of a program that benefits many…”  In other words, Marijuana should be treated just like any other controlled substance in the medical world, meaning its abuse needs to be monitored through government regulations and its therapeutic benefits researched and developed for those who qualify after failing other therapies.  An example of such is Sativex, which was approved and launched in the UK on June 21, 2010 (only a few days ago!), making it the first cannabis-based (taken directly from the plant) prescription medication in the world (vs. Marinol, a synthetic version of a chemical in the plant).    It can be prescribed for the treatment of neuropathic pain and spasticity in patients with multiple sclerosis as well as pain relief in adult patients with advanced cancer who experience moderate to severe pain.  In October 2009, the Obama Administration Department of Justice announced an end to federal raids by the Drug Enforcement Administration of medical Marijuana dispensaries that are operating in “clear and unambiguous compliance with existing state laws.”  At the same time, the battle for legalizing medical Marijuana is far from over (get the popcorn ready).

What does the future hold for medical Marijuana?

The 2010 Congressional Research Service states that, “With strong opinions being expressed on all sides of this complex issue, the debate over medical marijuana does not appear to be approaching resolution.”  So does that mean you should run out and purchase a bong at the nearest dispensary?  Using our most sound medical judgment, we would recommend against it due to the potential risks and side effects of Marijuana contrasted with your “medical need” for treatment.  As more research is unveiled in the upcoming years, perhaps the role for medical Marijuana will be more defined.  The take home message: Seek professional medical advice before starting any new treatments!

Questions? E-mail the Author: lee@myhousecallmd.com

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References:


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