Sunday, February 24, 2008

Marijuana Fact and Fiction

Why cannabis research is a good idea.

There is little doubt among responsible researchers that marijuana--although it is addictive for some people--is sometimes a clinically useful drug. However, there is little incentive for commercial pharmaceutical houses to pursue research on the cannabis plant itself, since they cannot patent it.

The use of marijuana in the treatment of glaucoma is well established. As for the relief of nausea caused by chemotherapy, the precise “antiemetic” mechanism has not yet been identified, but several studies show that marijuana works at least as well as the popular remedy Compazine for controlling nausea. Cancer patients have used marijuana successfully to increase appetite and combat severe weight loss.

Yet another intriguing possibility centers on Huntington’s chorea, the single-gene disease researchers spent years chasing down. Early data from the National Institutes of Health (NIH), reported in Science News, showed a loss of THC receptors in the brains of Huntington’s sufferers.

Queen Elizabeth believed that marijuana tamed her menstrual cramps back in the 16th Century, but there is no clinical and little anecdotal evidence to support this notion. Perhaps the anti-anxiety and mood elevating effects associated with marijuana are useful for menstrual irritation and mood swings, just as they are sometimes perceived to be useful by those suffering from depression.

The typical joint rolled in paper contains roughly 0.5 grams of plant matter, of which anywhere from 1 to 15 per cent is THC. THC content varies widely because some genetic strains of cannabis are more potent than others. This fact has led to intense debate in the United Kingdom over the issue of so-called “Skunk” marijuana. Skunk is not a new, lethally potent form of pot, but rather a shorthand term for describing one of several strains of strong, aromatic female marijuana plants. Most of the potent forms of marijuana for sale are hybrids resulting from cross-pollination of various strains. Of itself, “Skunk” marijuana is no more or less dangerous than other potent and popular varietals, such as “White Widow” or "Hawaiian Haze."

The half-life of marijuana is fairly short—about 50 hours for inexperienced users, and about half that for experienced users. However, THC and its metabolites are fat soluble, and are therefore easily stored in fatty tissue. Other drugs clear the system much more efficiently. The marijuana high may be history, but the metabolites live on--for up to 30 days. Blood tests can confirm THC in the body, but cannot reliably determine how recently the marijuana was smoked. There is no marijuana analysis kit comparable to the Breathalyzer test for alcohol. Drivers under the influence of cannabis may suffer some perceptual impairment. They tend to drive more slowly and take fewer risks, compared to drivers under the influence of alcohol. Possibly, cannabis smokers are hyperaware of the modest motor impairments they exhibit under the influence. Heavy drinkers are often unaware that there is anything wrong with their driving at all, as their sometimes-vociferous arguments with police officers and state troopers can attest.

As with cigarettes, chronic pot smoking can lead to chronic bronchitis. We don’t know for certain whether heavy marijuana use causes lung cancer, but it seems safe to assume that smoking vegetable matter in any form is not compatible with the long-term health of lung tissue. Patients with risk factors for cardiovascular disease are well advised not to smoke anything. Marijuana smoking can raise the resting heart rate as much as 30 per cent in a matter of minutes, and while there is no present evidence of harmful effects from this, we will have to monitor the situation more closely as pot-smoking and former pot-smoking Baby Boomers enter their cardiovascular disease years.

Other patients for whom marijuana is definitely not indicated include those suffering from respiratory disorders--asthma, emphysema, or bronchitis. In addition, schizophrenics or anyone at genetic risk for schizophrenia should shun pot, as it has been known to exacerbate or precipitate schizophrenic episodes—though it does not, as is commonly rumored, cause schizophrenia.

The evidence for significant impairment of cognitive function is equivocal—heavy marijuana use does not, like alcohol, result in gross structural brain damage. Numerous studies have addressed the possibility of subtler impairments in memory, attention, and the retention of new information. The extent to which such alterations are transient as opposed to long term is still under scientific debate.

Cannabis augments the effects of morphine in animal studies, thus allowing for a lower dose of opiates. Pain relief may be a primary attribute of anandamide—the brain’s own THC. Rats given the drug were less sensitive to pain than their non-drugged counterparts, as detailed in the Proceedings of the National Academy of Sciences. Drug companies may have closed the book on marijuana spin-offs too early. It would not be surprising if pills to selectively increase the amount of anandamide in the brain will one day augment or offer an alternative to existing anti-anxiety medications or pain relievers. On the other hand, a substance that blocks anandamide might find use as an agent to help combat memory loss.


For more, see: The Chemical Carousel: What Science Tells Us About Beating Addiction © Dirk Hanson 2008, 2009.

Related Posts: Anandamide: The Brain's Own Marijuana


E. R. Johnson said...

Actually there is quite a bit wrong with this article. I will focus on cannabis's patentability.

Sativex is an oromucosal (mouth) spray developed by the UK company GW Pharmaceuticals for multiple sclerosis patients, who can use it to alleviate neuropathic pain and spasticity. Sativex is distinct from all other pharmaceutically produced cannabinoids currently available because it is derived from botanical material, rather than a solely synthetic process.

Sativex is a pharmaceutical product standardised in composition, formulation, and dose. Its principal active cannabinoid components are the cannabinoids: tetrahydrocannabinol (THC) and cannabidiol (CBD). The product is formulated as an oromucosal spray which is administered by spraying into the mouth. Each spray of Sativex delivers a fixed dose of 2.7mg THC and 2.5mg CBD.

Approved by Health Canada under a license with conditions (NOC/c) for prescription use in April 2005, Sativex is the world's first artificial pharmaceutical prescription medicine derived from the cannabis plant. The product is approved in Canada as adjunctive treatment for the symptomatic relief of neuropathic pain in multiple sclerosis.

In June 2007, Health Canada issuing a Qualifying Notice for the approval of Sativex in the relief of cancer pain, with the final approval of this indication expected by fall 2007.

It is available in the UK as an unlicensed medicine which enables UK doctors to prescribe the product to individual patients who they consider may benefit. It is also available in Catalonia, Spain, for 600 patients suffering from multiple sclerosis and a number of other conditions under a compassionate access programme (130 of the patients will be people with multiple sclerosis, a further 130 will be patients with neuropathic pain arising from a range of medical conditions, 40 will be suffering from anorexia and malnutrition caused by AIDS, and the remaining 300 will be cancer patients undergoing chemotherapy and suffering from nausea and vomiting).

In February 2007, GW and Otsuka Pharmaceutical announced an exclusive agreement for Otsuka to develop and market Sativex in the United States. Sativex has received permission from the US regulatory authority, the FDA, to enter directly into late stage Phase III trials in the US.

The first large scale US trial in the US for cancer patients is expected to start in summer 2007. The 300-patient, double-blind, randomized, placebo-controlled study will evaluate the effect of Sativex in relieving average daily pain, reducing the use of breakthrough opioid medications, improving the quality of sleep and relevant aspects of quality of life among other outcome measures.
In December 2005, GW and the Spanish pharmaceutical company Almirall announced an exclusive agreement for Almirall to market Sativex in Europe (excluding the UK). In the UK and Canada, Bayer HealthCare have been appointed as exclusive distributors.

So much for the it can't be patented riff.

Dirk Hanson said...

My mistake--I should have made clear that I was referring to the marijuana plant itself.

There are plenty of examples of patents taken out for medications based on THC or THC-like compounds, such as Marinol and Dexanabinol.

If you believe you have discovered any errors of fact in the post, please let me know.

daksya said...

Numerous studies have addressed the possibility of subtler impairments in memory, attention, and the retention of new information. The extent to which such alterations are transient as opposed to long term is still under scientific debate.

Are you aware of the studies newer than the one you cited?

Neuropsychological performance in long-term cannabis users.

Neuropsychological consequences of regular marijuana use: a twin study.

Neurocognitive consequences of marihuana--a comparison with pre-drug performance

Dirk Hanson said...

Thanks for the recent cites, all of which bolster the hypothesis that neurological deficits related to pot smoking have not been proven to be long-term or permanent.

Corey said...

Pain and Movement

…basic biology indicates a role for cannabinoids in pain and control of movement, which is consistent with a possible therapeutic role in these areas. The evidence is relatively strong for the treatment of pain and, intriguing although less well established, for movement disorders. (Ch.2, IOM, 1999)

Anonymous said...

i am schizoid/bipolor and adhd.. no zombie though.. I do my homework with my meds... the best I can.. my schizoid/bipolar symptoms started in college when I stopped taking my stimulants for awhile.. abrubt cease in regular childhood stimulant intake combined with early college drinking... can effect "dope"-amine levels.. I believe this can cause long term schizoid symptoms more than the temporary effects of pot.

I also take an antihistamine for nasty extra pyramidal side effects from my antipsychotic... this also balances my histamine levels that seem to help my dopamine issues.. which keeps anxiety in check and makes me less likely to indulge in alcohol..

pot is the ultimate sedative aid for me.. when used daily.. I am just as high functioning as anyone... I get good grades in school and I am able to technical and creative things like hack linux and build web apps.. the point is though, I have no need or desire to drink anymore..... and at times in life I have even been homeless and alcoholic.. but this was when I was living in a different place and didnt have any access to pot... and I was on an ssri and antipsychotic.. I was manic and contorted as hell.. and alcohol was all I could find for temp relief... but it only made matters worse for me

If there was an western english speaking country with legalization.. I would move there. the war on pot is a war on the ill especially. it spawns hatred of those who enforce enforce the law and for those peaceful consumers who the law admonishes.

IMHO pot, in its natural unpatented form, is an easy scapegoat. its not fair.. and current events will only get worse because there is no such thing as peaceful oppression... if only the religious right ate pot instead of drinking wine.. I am sure our control hungry governments would be in a different position entirely

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