POT DEBATE LINGERS ON

Published: August 19, 2008 11:00 PM Dear Sir:

When I read the letter by Mr. Davidson (Pot is a low-cost medicine
that can help sick people) in the Aug. 6 issue, I considered ignoring
it and leaving it at that. However, after a few days I felt that some
more science is appropriate to clear up issues that were stated that
are scientifically incorrect.

I am not a crusader against pot, rather a scientist and a
Pharmacologist (Ph.D.) at that and not an M.D. as is assumed in the
letter. I actually teach this sort of subject matter and feel very
strong about non-evidence based ideas in the public on matter such as
these.

I will address only one of the issues here and leave the others for
subsequent letters to keep them reasonably short.

My quarrels with pot, as I stated in the letter that triggered the
response by Mr. Davidson is the ?smoke? and not the active ingredient.

To clarify this aspect: Tetrahydrocannabinol (THC accompanied by a
large number of related compounds in the plant) is the active
ingredient in pot.

Two approved drugs that act like THC are available for prescription in
Canada. Nabilone (Cesamet(R)) is a man-made THC-related drug, which is
superior to natural THC because it does cause little to no euphoria
while effective against nausea and pain. Sativex(R) is a combination
of THC and cannabidiol actually extracted from marijuana. It is as
effective as Nabilone but accompanied by psychoactive ?adverse effects?.

THC actually acts via several different receptors in the brain. Only
some are responsible for the beneficial effects on nausea and pain,
the others for the desired high. The synthetic drug in Cesamet(R) was
designed to bind to only the nausea-pain type receptors so as to avoid
patients developing addiction to such medications.

Of course that might be a disappointing achievement for those who
don?t care about the addiction problem but want to feel high. It seems
Sativex(R) or pot cookies are their preferred medications.

One might even go as far as extracting all naturally occurring
cannabinoids from marijuana (over 60 in all) and use them in some
preparation. That is actually technically easier than isolating pure
THC.

Modern pharmacology tries to avoid using such a concoction of
compounds because with every added chemical the effects become more
complex and unpredictable.

It is long-standing practice to figure out why plant-derived materials
are beneficial, isolate what is responsible for it and use it in a
predictable, safe formulation. There are dozens of drugs like that
indispensable for modern medicine. Morphine, atropine, scopolamine,
digoxin, vinblastin, taxol are some examples.

As per the route of administration, inhaling drugs causes a very fast
entry into the blood stream and brain. That might be a good thing if
you need action fast i.e. laughing gas pain treatment at the scene of
an accident. For drugs that trigger pleasure it very much increases
the addiction potential. The reason for this is that the association
with administering the drug and the pleasure is much closer than after
oral administration.

My comparison to fast food was misunderstood here. I did not mean that
fast foods have any medicinal application. My analogy of fast food as
being somewhat addictive has the same reason for what I had just explained.

Eating food to satisfy hunger causes pleasure. The hungrier you are
the more pleasure (dopamine release in certain areas in the brain) is
rewarded from eating. Nature has put this reward into our physiology
so we take care of our food intake. It is a basic survival mechanism.

You could make ?fast foods? at home yourself. Go to the store and buy
ground beef, potatoes, condiments, buns, walk home, start the BBQ,
etc. you know where this is going. By the time you get your pleasure,
you have spent a good hour of work to get there. Walk into a fast food
place and five minutes later you can be full. That is why it is so
attractive to do this. That is conditional learning common to all
animals par excellence.

If there is any interest I will address the following issues as well,
because they are left misconstrued: How do you extract THC from pot?
Is it a good sign that THC does not cause death in overdose? Is pot
smoking beneficial in asthma patients? Is marijuana addictive or not?
Why does THC not cause withdrawal symptoms? Are natural plants/herbs
really better medicines than man-made chemicals? Are today?s drug
companies money-making corporation that cause more harm with their
products than good?

Dr. John Krisinger

Dept. of Biology & Nursing

Northwest Community College