From:
sukie crandall
Date: 2005-04-15 21:06:11 UTC
Subject: pharmacognosy: licorice root
To: ferret-list <ferret-list@cunyvm.cuny.edu>, ferrethealth@smartgroups.com
Message-id: <1774be1f563ff8f99fb47b63ba5b778e@optonline.net>
Pharmacognosy is the study of the medicinal uses of natural compounds.
The qualifications of people who offer advice in natural medicine vary
through the complete gamut from those who do not take risk factors into
account (usually because they innocently have not done their homework
well enough, but sometimes because they choose not to) all the way to
those with advanced degrees. BUT the degrees can vary, too. There is
at least one rumor mill offering titles based on little to no real
knowledge or experience, while at the same time there are graduate
programs in pharmacognosy at the pharmacology departments of some very
respected, accredited universities.
Okay: licorice root -- very natural and, hey, it is used as a flavoring
for some candies (though many now use artificial licorice flavoring or
use anise which does not carry the risks of licorice) so you would
figure it is safe. Right? Nope. It is known to be potentially very
dangerous for humans and from hearing of too many ferrets beating the
odds in a bad way for problems like throwing clots (thromboses) or
having a shortened lifespan with cardiac problems I am not personally
inclined to consider it safe for ferrets, though I will be frank and
say that I have not to date found actual REAL research into ferrets and
licorice root even checking in places like Pubmed. Still, the effects
are of such a basic nature that it is far better to be safe than to be
very sorry.
Licorice, Glycyrrhiza was studied carefully for treating ulcers during
WWII by a Dutch physician, F.E. Revers who found that it did help the
ulcers BUT EVEN IN THAT SHORT TRIAL 20% OF THE PATIENTS DEVELOPED
EDEMA, a very scary sign which fortunately stopped when the licorice
was stopped. Since then a great many studies have shown the dangerous
effects licorice can have on the heart, headache, etc.
Dr. Varro Tyler, Distinguished Professor Emeritus of Pharmacognosy at
Purdue University is also past president of the following four
respected associations: The American Society of Pharmacognosy (1st
president), the American Association of the Colleges of Pharmacy, the
American Council on Pharmaceutical Education, and the American
Institute of the History of Pharmacy. On licorice he notes: "These
undesirable effects are mineralcorticoid in nature. Specifically, they
include headache, lethargy, sodium and water retention (the edema noted
by Revers), excessive excretion of potassium, and high blood pressure.
Eventually, heart failure or cardiac arrest may result."
(It is interesting to notice that is it increased hydrocortizone
levels. I will have to check back through some past vet posts, but
wasn't there a postulated possible negative effect on the pancreas of
ferrets (I seem to maybe recall a hypothesis for a diabetes -- a rare
problem in ferrerts -- connection.). I'll have to check later, or if
someone else feels like doing so -- check in past FHL vet posts since I
think that may where I either read it or read something I am mixing up
with it .) Another Varro Tyler text refers to licorice mimicing
excessive secretion of the adrenal cortex hormone aldosterone to the
point in humans where is can cause pseudoaldersteronism. It would be
interesting to know if giving herbal compounds contain licorice has
thrown off diagnoses of adrenal disease in some ferrets.
Among humans the German Commission E approved the use of licorice in
humans who have ulcers BUT only for a very limited time and at low
doses and lists a wide range of people who should not use it even with
those precautions (including those with heart disease, those who are
elderly, those who have liver or kidney problems, those who are already
low in potassium, etc.). The appropriate PDR notes some other uses but
also with strict cautions. This is an easily abused, powerful herb
which can pack some high risk factors.
Most natural licorice imported into the U.S. is used to favor tobacco.
I do not know how much of the dangerous compounds might be in second
hand smoke since some is in smoke tobacco rather than chewed tobacco
(Never swallow the fluids created by chewing tobacco; it's bad enough
without doing that, but so is smoking, of course.)
Tyler further notes that the levels recommended in one popular homemade
cough remedy can reach toxic levels in only a week nof use in humans,
and be dangerous much sooner for those with certain illnesses or
vulnerabilities already in place.
In the _Herb-Drug Interaction Handbook_ Sharon Herr, RD has a list of
drug interaction combinations when licorice is being taken (a few good,
most bad) that extends over 4 pages. A number are heart drugs and
diuretics, but it also alters Pred, and can have very bad effects in
those taking insulin, including hyperglycemia, loss of blood glucose
control, electrolyte imbalance, etc. When taken with corticosteroids
she notes that increased potassium loss. The interaction with
glucorticoids is also mentioned as a caution in _Manual of Natural
Veterinary Medicine, science and tradition_, as are cautions for heart
meds, diuretics, its potential to cause clotting dangers. It will be
no surprise to you that it is listed in a book on poisons I have here.
Finally, the _PDR for Herbal Medicines_ notes names it might be sold
under other than "licorice" or its taxonomic name, so also watch out
for the terms "Phyto Power" and for "sweet wort". It also notes that
licorice inhibits the kidney's conversion of cortisol into cortizone
and this in turn drops serum potassium levels, etc. that lead to high
blood pressure.
Contraindications mentioned (in humans) include: chronic hepatitis,
cholestatic diseases of the liver, cirrhosis of teh liver, renal
insufficiency, diabetes, arrythmias, hypertension, hypertonia,
hypokalemia, and pregnancy. It also says that taking it for a long
period of time can result in hypokalemia, hypernatremia, edema,
hypertension, and cardiac complaints. there is a section on
endocrinological cautions with symptoms including lethargy,
paresthesias, muscle cramps, headaches, etc.) and on how it can cause
acute renal failure, and parts about profound deposition into damaged
skeletal muscles and cardiac muscles. It can cause Dogoxin toxicity if
given with a safe dose, and (again) has dangerous interactions with
multiple diuretics, and carries other heart risks such as potentiating
"severe ventricular tachycardia of the torsades de pointes type" In
rare cases in humans myoglobinemia has occurred.
I personally suggest, based solely on what I have learned from such
references as those above, that you use extreme caution with licorice
-- that if you want to use it that you first do your own homework
looking in these references (Use an interlibrary loan if you must.) and
testing before giving the stuff to make sure that there are no health
or medicine reasons to not give it, and if you do give it to use only a
small dose and only for a very short time to avoid setting the stage
for heart damage and other health problems. Seriously, my own personal
take on this is that you WANT to AVOID this ingredient if you can, so
check those labels and do your own reading to see what conclusion you
come to. Don't read only the good about ANY medication. Also always
read the timing, dosing, cautions, conflicts, counter-indications, and
how long is too long to give a certain med -- herbal or not -- so that
the results of your actions best match the level of love you have for
your ferrets.