Marijuana As Medicine? The Science Beyond the Controversy (2001) / Chapter Skim
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Can Marijuana Help?
Can Marijuana Help?
Pages 13-37
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From page 13... ...
Basic studies have been conducted to characterize the chemicals found in marijuana, their interactions with molecules and cells in the human body, and their effects on experimental animals. The most readily available information on medical marijuana can be found in historical documents some more than a thousand years old as well in the personal stories of people who have taken the drug to relieve medical symptoms.
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From page 14... ...
The medicinal use of smoked marijuana is largely a recent phenomenons According to Chinese legend, the emperor Shen Nung (circa 2700 B.C.; also known as Chen Nung) discovered marijuana's healing properties as well as those of two other mainstays of Chinese herbal medicine, ginseng and ephedra.
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From page 15... ...
During the Renaissance, reports from explorers in Asia, Africa, and the Middle East piqued the interest of European herbalists, who also consulted the writings of Galen, Pliny, and other ancient physicians. Nevertheless, medical marijuana continued to be a rarity in the West.6 Meanwhile, demand for hemp fibers as a material for making rope and textiles especially canvas for sails grew so strong that by the sixteenth century European nations commanded their colonies to grow the crop.
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From page 16... ...
They told of treating cramps, headache, asthma, diabetes, impotence, acute and chronic pain, fever, appetite loss, and scores of other conditions with the plant. On the basis of this testimony, members of the commission concluded that marijuana represented one of the most important drugs in the Indian pharmacopoeia and that "moderate use of hemp drugs is practically attended by no evil results at all." Thus, the commission recommended against marijuana's prohibition, despite acknowledging the problems posed by its abuse as an intoxicant.9 At the first American conference on the clinical use of marijuana, held by the Ohio State Medical Society in 1860, physicians reported success in using marijuana to treat chronic cough, gonorrhea, pain, and a variety of other conditions.
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From page 17... ...
As with cannabinoids, the human body produces its own version of opiates, known as endorphins. These compounds interact with nerve cells in the same way as their plant-derived relatives, with similarly soothing results.
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From page 18... ...
As a result, many doctors hesitate to prescribe opiate medications except in extreme cases. Nevertheless, opiate abuse is so widespread that the illegal demand for opium far exceeds legitimate medicinal sales of the drug.~2 More than a century after opium abuse spread across the globe, marijuana gained worldwide popularity as a recreational drug.
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From page 19... ...
In the 1970s and 1980s several states even supported limited clinical studies on medical marijuana. Voters in several states have passed referenda intended to permit marijuana use for medical purposes (see Chapter 11~.
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Patients described using marijuana to treat AIDS wasting, spasticity from multiple sclerosis, depression, chronic pain, chemotherapy-induced nausea, and other symptoms. Similar accounts of medical marijuana use in treating an even broader range of conditions appear in Marihuana: The Forbidden Medicine, by Lester Grinspoon and lames Bakalar.~3 AIDS was the predominant disorder described by medical marijuana users who told their stories to the IOM study team.
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From page 21... ...
So, for my third and fourth courses of chemotherapy, I smoked marijuana. None of my doctors and nurses discouraged me from doing this.
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From page 22... ...
Next to AIDS and chemotherapy-induced nausea, pain appears to be the most frequently cited reason for using medical marijuana. Like several individuals who addressed the IOM team, the following man found that marijuana improved the effectiveness of the narcotic medications he was already taking for pain: I am a 35-year-old father [and]
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From page 23... ...
The surviving participants include this 41-year-old woman who managed her family's men's wear store until she developed multiple sclerosis. She smokes marijuana to relieve several symptoms of multiple sclerosis: I was diagnosed with multiple sclerosis in 1988.
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From page 24... ...
Indeed, patients in several clinical studies have occasionally had adverse reactions to smoked marijuana, including anxiety, panic, and paranoia. These short-term effects appear to occur mainly among first-time and older users.~4 It seems doubtful that anyone who reacted this badly to a medication would want to continue taking it, but it is unclear how many potential users of medical marijuana would fall into that category.
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From page 25... ...
Thus, for any given symptom the potential exists to discover numerous drugs that reinforce each other's effects, because each affects a unique link in the causal chain. Several basic studies indicate that marijuana acts differently from conventional treatments for a variety of conditions, so it may prove to be a valuable source of auxiliary medicines.
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From page 26... ...
And because cannabinoids degrade when exposed to high temperatures, moisture, and sunlight, storage conditions strongly affect the cannabinoid content of dried leaves or flower tops. More than 60 different but closely related cannabinoids have been isolated from marijuana.
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From page 27... ...
Live marijuana plants and dried plant parts contain all of these cannabinoids as well as others that represent either precursors of THC or modified versions of the THC molecule. CANNABIS AND THE CELL Although it has long been observed that marijuana alters thinking and behavior, scientists have only recently begun to learn how chemicals in marijuana act on individual cells, both in the brain and elsewhere in the body.
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From page 28... ...
This might slow a person's reaction time enough to make driving hazardous, but the same process could also dull pain signals traveling along those nerves, thereby providing some pain relief. Likewise, when THC binds CB2 receptors on white blood cells, it may impede their natural response to infection a bad thing if it lowers a person's resistance to disease but a good thing if it reduces painful inflammation.
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From page 29... ...
Another factor that limits anandamide's activity is a phenomenon known as reuptake, the rapid reabsorption of certain types of neurotransmitters after their release from nerve cells (see Figure 2.6) , which protects neighboring nerve cells from over-stimulation.
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From page 30... ...
Signal transmission between two neurons (nerve cells) begins as the sending neuron releases chemical messengers called neurotransmitters.
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From page 31... ...
When cannabinoids bind to these receptors, they typically set off a chain reaction that slows the transmission of nerve impulses between cells. That is not always the case, however; in other nerve cells, CB~ receptors are arranged in such a way that they speed the delivery of messages along neural pathways.
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From page 32... ...
Several regions of the brain, which govern a wide range of body functions, contain high concentrations of cannabinoid receptors. Abundant cannabinoid receptors are also present in the following areas not shown in this view of the brain: the basal ganglia, which controls movement; the nucleus of the solitary tract, which governs visceral sensation, nausea, and vomiting; the nucleus acumbens, the brain's reward center; and the central gray area, which registers pain relief.
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From page 33... ...
Cannabinoids also appear to play a role in pain transmission along peripheral nerves, which detect sensations in all parts of the body and relay messages to the brain via the spinal cord. Peripheral nerve cells display both CB~ and CB2 receptors on their surfaces, and research in experimental animals indicates that cannabinoids specific to each receptor type appear capable of blocking peripheral nerve pain.
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From page 34... ...
Many of these reports focus on the effects of THC on one of several species of white blood cells, the workhorses of the immune system. Each type of white blood cell serves a different purpose, and all function in concert to defend the body against disease.
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From page 35... ...
In some experiments, certain cannabinoid drugs have been shown to depress the production of cytokines, hormonelike chemicals that direct immune cells to eliminate foreign substances from the body. Cannabinoids have also been shown to reduce inflammation and tissue damage in rat brain models of head injury, meningitis, and multiple sclerosis.
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From page 36... ...
By following a similar path, medical researchers have learned to harness the benefits and minimize the risks associated with opiate drugs. Basic studies have also identified several potential health risks associated with marijuana and cannabinoids, which are discussed in the next chapter.
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From page 37... ...
1999. Marijuana and Medicine: Assessing the Science Base.
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