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Q: Is it safe to combine warfarin and glucosamine? ( Answered 3 out of 5 stars,   2 Comments )
Subject: Is it safe to combine warfarin and glucosamine?
Category: Health > Medicine
Asked by: tadeusz-ga
List Price: $15.00
Posted: 07 Oct 2003 04:40 PDT
Expires: 06 Nov 2003 03:40 PST
Question ID: 263397
I am on warfarin (a prescribed anticoagulant)for life. I wish to take
glucosamine also for its anti-arthritis qualities. I know from health
food supplement advertisements that glusoamine is often combined with
chondroitin, and from my own research I know that chondroitin is not
recommended for those taking warfarin as it has an effect on the
'stickiness' of blood. I think that pure glucosamine on its own is OK,
but cannot find evidence of this. Can you please confirm that pure
glucosamine does not have an effect on the INR (time it takes for
blood to coagulate)?
Subject: Re: Is it safe to combine warfarin and glucosamine?
Answered By: pinkfreud-ga on 07 Oct 2003 07:37 PDT
Rated:3 out of 5 stars
Like many arthritis treatments, glucosamine (even when used without
chondroitin) may possibly have hematologic effects that could cause it
to interact with warfarin. However, the evidence is far from
conclusive. Below you'll find selected excerpts from web pages which
discuss the matter.

"An increase in the International Normalized Ratio (INR) was noted
when glucosamine was administered to patients receiving warfarin. INR
values decreased when glucosamine was stopped."

Arts en Apotheker

"Chondroitin and heparin, a drug used to thin the blood, are similar
in chemical composition. For this reason, some researchers speculate
that people may suffer bleeding complications from chondroitin,
particularly when it is used in combination with other blood-thinning
medications, such as aspirin, warfarin, or heparin. For people who are
taking blood-thinning medications, it is wise to first consult a
healthcare practitioner before trying chondroitin."

USA Drug 

"Chondroitin sulfate... May increase the effects of anticoagulants /
blood thinning drugs & herbs heparin, warfarin/coumadin, aspirin)"

Hospital for Special Surgery

"The Arthritis Foundation does not currently recommend the use of
chondroitin. if chondroitin sulfate is taken, it could very well
interact with anticoagulants such as warfarin or heparin and cause
increased bleeding tendencies."

Howard University Hospital

On the other hand, there are reputable sources that indicate no
serious interaction between glucosamine and warfarin:

"Hematologic effects have been a concern. Chondroitin sulfate and
GAGPS have a heparinoid structure. Parenteral glycosaminoglycans can
prolong the prothrombin time, the partial thromboplastin time, and
decrease platelet aggregability. A number of trials noted no
significant effects on the complete blood count when oral glucosamine
or oral chondroitin sulfate were given separately. In dogs, the
combination oral preparation produced minor transient decreases in
hematocrit and white blood cell count; decreases in platelet count and
aggregability; but no change in bleeding or clotting times. Despite
statistical significance of some changes, values stayed within the
normal clinical range."

U.S. Navy Seals Oesteoarthritis tests

"There are no reports in the literature of an interaction between
glucosamine and warfarin. There is no particular reason why
glucosamine should interact with warfarin since it is not metabolised
by the cytochrome P450 system, but is instead broken down in general
metabolism via the carbohydrate pathways. The serum level of
glucosamine is very low even immediately following a dose, so a direct
interaction is also unlikely. Our in-house experience with glucosamine
adverse reactions has not (to date) involved a case of warfarin
sensitivity. Finally, in many clinical trials no such interaction has
been reported. Again, if in doubt it is recommended you consult with
you health care adviser."

Arkopharma Australia

Here you'll find a collection of links to articles which provide
information about glucosamine:

The Arthritis and Glucosamine Center

Search terms used:

"glucosamine" + "warfarin"
"glucosamine" + "coumadin"
"glucosamine" + "heparin"
"glucosamine" + "hematologic effects"
"glucosamine" + "blood thinner"
"glucosamine" + "anticoagulant"
"glucosamine" + "prothrombin"
"glucosamine" + "clotting"
"glucosamine" + "inr"

If you should decide to try glucosamine, I strongly recommend that you
tell your physician. He or she may want to monitor your International
Normalized Ratio (INR) to keep a close look at your prothrombin time.

I hope this helps! Please keep in mind that Google Answers is not a
source of authoritative medical assistance; the material I've
presented above is not intended as a diagnosis, nor as a substitute
for the services of a qualified medical professional.
If anything is unclear, or if a link does not function, please request
clarification; I'll gladly offer further assistance before you rate my
Best wishes, 
tadeusz-ga rated this answer:3 out of 5 stars
The answer was helpful, but did not provide conclusive evidence one
way or the other. This may be the safest and best way to go,
especially in matters of health, but I was hoping for a definitive
answer. Perhaps the research is unclear and there isn't such an

Subject: Re: Is it safe to combine warfarin and glucosamine?
From: pinkfreud-ga on 08 Oct 2003 10:25 PDT
I am sorry my answer disappointed you. If you feel that I have
overlooked conclusive evidence on this subject, you may want to obtain
a refund and repost your question so that another Researcher may
assist you.
To apply for a refund:    

Subject: Re: Is it safe to combine warfarin and glucosamine?
From: pugwashjw-ga on 10 Oct 2003 06:50 PDT
Hi Tadeusz, I`m in a similar situation, heart problem, and my doctor
has me on aspirin for blood thinning, not Warfarin. Using Warfarin
seems the hard way to go. I wouls question your doctor on whether it
is absolutely necessary in your case. It may be. As for your
arthritis, my old mum, now passed away at 84, was able right up to age
83, able to touch the ground with the flat of her hands, bending at
the waist. She never had a touch of arthritis. Her treatment?? A daily
dose of EPSOMS SALTS in a glass of warm water, EVERY MORNING. It takes
w while to build up in your system, maybe some months, But it does
WORK. Its up to you if you wish to try it. hope it helps.. Pugwashjw.

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