is derived from coumarin -- a naturally occurring chemical compound with
anti-clotting properties found in many plants.
It thins the blood and was originally used as rat poison. Treatment reduces the risk of thrombosis (blood clots), but makes patients
more liable to bleeding and use is associated with an increased
risk for brain hemorrhage. Warfarin is effective at reducing the risk of
stroke in atrial fibrillation.
Warfarin is one of the most widely used drugs taken by 2 million patients to prevent blood clots that can cause heart attacks and strokes. It is also sold under the brand name Coumadin by Bristol-Myers Squibb .
Natural supplements and
Certain supplements have blood thinning potential and should be used with caution by those who are on blood thinning medication. See blood clot for more information. Consult with your doctor. It is possible that the use of certain supplements, or dietary changes that include more fish, spices and vegetables, could reduce the dosage required for warfarin. Natural supplements that thin the blood include:
Chamomile is a
mild relaxer and has very mild blood thinning activity. Canadian doctors describe the case of a 70-year-old woman,
while being treated with warfarin, who developed severe internal bleeding after
drinking chamomile tea to soothe a sore throat and applying chamomile lotion to
relieve chest congestion and reduce foot swelling. While warfarin is known to
interact with garlic, onion, and ginger, this is believed to be the first
documented case of a drug-herb interaction between warfarin and chamomile. In the present case, the woman had received a
mechanical heart valve implant and was taking warfarin to reduce the risk of
blood clots. Canadian Medical Association Journal, 2006.
CoQ10 supplement - Is Coenzyme Q10 safe to take in those who are on warfarin therapy? The results from studies have been inconsistent, and my impression is that low dosages of 30 mg a few times a week should not interfere with warfarin medication.
Cranberry juice, sauce or cranberry supplements thin the blood and increase INR levels in patients who are taking warfarin pills.
Dong quai herb is a Chinese herbal supplement which has natural coumarin derivatives. Dong quai increases the effect of warfarin, increasing the risk of bleeding; therefore, co-administration is contraindicated.
EGCG, the extract from green tea, may prevent platelet aggregation as potently as aspirin.
Fish oils thin the blood and their risk in combination with warfarin depends on the dose of the fish oils and the dose of the blood thinner. Those who take fish oil pills may need to reduce their dose of prescription anti-coagulants since it is possible that the INR can increase with supplementation.
Cayenne supplement may increase the risk of bleeding with the use of warfarin medication.
Garlic is a mild blood thinner.
Ginger may increase bleeding risk in those who are taking warfarin pills.
Ginkgo biloba is a Chinese herb used for mental enhancement and alertness and is one of the most widely used herbal products in the United States. However, bleeding episodes in patients taking ginkgo biloba and warfarin have been documented. Ginkgo extract inhibits human liver microsomal CYP2C9.
Nattokinase is a potent blood thinner compared to other natural herbs and supplements. Always consult with your doctor before taking nattokinase, particularly if you are taking warfarin.
St. John's wort may increase the risk for bleeding when used together with warfarin medication.
Vitamin K helps blood coagulate.
White willow bark supplement
This is a partial list.
CoQ10 and warfarin
Effect of Coenzyme Q10 and Ginkgo biloba on warfarin dosage in patients on long-term warfarin treatment. A randomized, double-blind, placebo-controlled cross-over trial.
Ugeskr Laeger. 2003. Engelsen J, Nielsen JD, Hansen KF. Klinisk Biokemisk Afdeling, Koagulationslaboratoriet, Amtssygehuset i Gentofte, Niels Andersens Vej 165, DK-2900 Hellerup.
A few case-stories claim that the anti-oxidant Coenzyme Q10 and possibly also Ginkgo biloba interact with warfarin treatment. A decreased response to warfarin in the Coenzyme Q10 cases and an increased response in the Ginkgo biloba case have been described. Twenty-four outpatients on stable, long-term warfarin treatment were included in a randomised, double blind, placebo-controlled crossover trial. Coenzyme Q10 100 mg daily, Ginkgo-Biloba 100 mg daily and placebo were given in random order over treatment periods of four weeks, each followed by a two week wash out period. The international normalized ratio (INR) INR was kept between 2.0 and 4.0 by appropriate adjustment of the warfarin dosage. Fourteen women and ten men, median ages 64.5 years (33-79) were included. Three patients withdrew from the study for personal reasons. The INR was stable during all treatment periods. The study indicated that Coenzyme Q10 and Ginkgo biloba do not influence the clinical effect of warfarin.
Warfarin side effects,
Hemorrhage (bleeding) is one of the most common and serious risk associated with warfarin therapy. The bleeding can occur in practically any tissue or organ. The signs, symptoms and severity of the bleeding and subsequent complications vary according to the location and degree of bleeding. Haemorrhagic complications may present as headache, hypotension, chest, abdomen and muscle pain, red blood in stools or black stool. Other side effects of warfarin therapy are necrosis of the skin or skin rashes, priapism, headache, and dark urine. Risk factors significantly associated with increased bleeding included high target INR (2.5 to 3.5), diarrhea, acetaminophen use, alcohol consumption, and increased age.
Warfarin side effects - Osteoporosis
The long-term use of warfarin appears to increase the risk of fractures associated with osteoporosis, a bone-thinning condition that usually increased with age. Warfarin prevents coagulation by blocking vitamin K, which is needed to activate certain clotting factors. Because vitamin K is also used to activate proteins involved in bone formation, drugs like warfarin may increase the risk of fractures. To investigate, Dr. Brian F. Gage, from Washington University School of Medicine in St. Louis, and colleagues assessed the rate of osteoporotic fractures among 12,048 Medicare beneficiaries. The subjects included 4,461 who had been prescribed warfarin for at least one year and 7,587 who were not on the drug. Warfarin users were 25 percent more likely to experience a fracture than nonusers. However, this relationship was statistically significant only in men. Further analysis of data from 1,833 patients who were on warfarin for less than one year did not detect a statistically significant increase in fracture risk. Risk factors for fracture included older age, high risk of falling, overactive thyroid, neurological or psychiatric disorders, and alcoholism, the report notes. When prescribing warfarin to elderly patients at high risk of falling, healthcare providers can instruct them to wear stable shoes, exercise regularly, have adequate intake of calcium and vitamin D, use walking aids, and discontinue unnecessary medications. Archives of Internal Medicine, January 23, 2006.
Trauma and injury
Warfarin may also cause problems for individuals who suffer some form of trauma, particularly the elderly. Trauma patients who take warfarin at the time of their injury are at increased risk of dying compared with trauma patients not on the anti-clotting drug.
Warfarin diet, food
The effect of warfarin decreases after initiation of a high-protein, low-carbohydrate diet.
It's quite likely that alcohol interferes with warfarin metabolism and effect. Hence, it is preferable to avoid drinking more than one glass of alcohol a day. Wine has compounds called flavonoids that thin the blood.
Warfarin and stroke
Warfarin appear to be the best treatment option to prevent stroke in patients with an abnormal heart rhythm despite side effects such as risk of bleeding. A trial of patients with the disorder known as atrial fibrillation uncovered evidence that it was superior to the combined treatment of the blood-thinner Plavix plus aspirin in reducing strokes.
Short-term interruption of warfarin therapy is associated with a low risk of thromboembolism.
Warfarin drug interaction
Non-selective non-steroidal anti-inflammatory drugs (nNSAIDs) used in combination with warfarin are associated with an approximately 3-fold increased risk of upper gastrointestinal bleeding compared with warfarin alone.
For women taking warfarin to prevent blood clots, a single dose of fluconazole to treat a vaginal yeast infection can lead to an increased risk of bleeding. The time taken for blood to clot -- the so-called prothrombin time -- should therefore be carefully monitored in this scenario, and a change in warfarin dose may be needed. Fluconazole (brand name, Diflucan) is a common treatment for vaginal candida infections, and is known to interact with a number of drugs, including warfarin -- which can give rise to serious bleeding complications.
In older patients on warfarin therapy, treatment with cotrimoxazole significantly raises the risk of upper gastrointestinal tract hemorrhage. The increased hemorrhage risk is considerably higher than with other commonly used antibiotics. Compared with amoxicillin or ampicillin, for example, cotrimoxazole increased the risk of upper GI tract hemorrhage by almost three-fold. Arch Intern Medicine 2010.
Elderly patients as a group may present more of a challenge in managing warfarin therapy because of alterations in pharmacokinetics from other medications, diet, and disease; pharmacodynamic changes; increased risk for hemorrhage; and difficulty in monitoring. The elderly, however, may derive the most benefit from warfarin therapy for certain indications, such as the prevention of stroke in atrial fibrillation or recurrent events following deep venous thrombosis.
Self-Monitoring while on the
Self-monitoring by patients taking anti-clotting drugs such as warfarin is safe, effective and could lead to fewer deaths. Anticoagulants, or blood thinners, such as warfarin or coumadin, are a common treatment to prevent blood clots and strokes. Millions of people take the drugs but their reaction to the treatment must be tested regularly to prevent bleeding or hemorrhage. Patients who monitor their own treatment with a home testing kit and adjust their dose suffer fewer blood clots and deaths than people tested by medical professionals. Self-monitoring involves taking a blood sample from a pin prick and putting it into a home testing kit. The machine gives a reading that shows if the patient is in a safe range and not at risk of bleeding or having a blood clot, or if the dose needs to be adjusted. Monitoring is done almost daily in the early days of treatment and reduced over time to about once a month.
Warfarin Increases brain
The rate of brain hemorrhages associated with blood thinning drugs quintupled during the 1990s, according to a study published in the January 9, 2007, issue of Neurology, the scientific journal of the American Academy of Neurology. In people over age 80, the rate increased more than tenfold. Most of the increase is due to greater use of the drug warfarin, which is commonly prescribed to prevent blood clotting. Blood clots can lead to ischemic stroke, the most common type of stroke. An intracerebral brain hemorrhage is a stroke caused by bleeding in the brain. The use of warfarin increased after studies showed it reduced the risk of stroke caused by blood clots for people with atrial fibrillation, a condition that causes irregular heart rhythm and becomes more common as people age. "Warfarin is highly effective in preventing ischemic stroke among people with atrial fibrillation," said study author Matthew L. Flaherty, MD, of the University of Cincinnati. "For many people, the benefits of preventing ischemic stroke continue to outweigh the risk of a hemorrhagic stroke. Doctors can use these findings to make sure they are weighing the risks and benefits of warfarin use for their patients. For the study, researchers identified all patients in the greater Cincinnati area hospitalized with a first-time intracerebral hemorrhage during three years: 1988, 1993-94, and 1999. In 1988, the annual rate of intracerebral hemorrhages associated with use of blood thinning drugs was.8 cases per 100,000 people. In 1999, the rate was 4.4 cases per 100,000 people. For people age 80 and older, the rate increased from 2.5 in 1988 to 45.9 in 1999. The study was supported in part by the National Institute of Neurological Disorders and Stroke.
Risk of bleeding
Elevated blood concentrations of the soluble thrombomodulin antigen, a transmembrane glycoprotein expressed on the endothelial cell surface, are associated with an increased risk of bleeding during warfarin treatment. Arch Intern Med 2009;169:1210-1215.
Warfarin and interactions with
herbs and supplements questions
Q. Can you tell me if there are any contraindications between Passion Rx and warfarin (Coumadin)?
A. We have not tested blood coagulation parameters with Passion Rx so we don't know if the herbs influence blood thinning or coagulation or have no effect. Most of the time Coumadin or warfarin is taken by those who have a heart condition or atrial fibrillation, and we do not suggest people with a heart condition take Passion Rx or most of the sex herbs.
Q. Are there any contraindications for lipoic acid
being taken with warfarin? I have DVT and have been on the blood thinner for 3
A. We have not come across such interaction between warfarin and lipoic acid at this time, but we are not aware of any testing that has been done with these two together.
Q. My question is does taking
reishi capsules interfere
with the warfarin? I take 5mg a day.
A. We checked Medline for the keywords reishi in association with warfarin, bleeding, platelet, clotting, Coumadin, and could not find any research.
Q. Is saw
palmetto (serenoa repens) okay to take with warfarin? What about
A. Probably, but I have not seen such research regarding serenoa repens. As to serrapeptase, I would hold off using it with warfarin for now till I see some human trials.
Q. Can warfarin be taken the same day as an
A. We have not seen any studies with this combination, so it is difficult to say for sure.
Q. Is Mind Power Rx a blood thinner? I am on warfarin
at this time.
A. We have not done coagulation blood studies with Mind Power Rx do determine whether it has any influence on blood coagulation or how it would interact with warfarin. There are a dozen nutrients and herbs in this product in small quantities each, and we don't know how this combination influences clotting or platelet aggregation. Many people just take Mind Power Rx one capsule two or three days a week, and it is unlikely that this would have much of an influence on clotting but we can't be 100 percent sure.
In July of 2006 I under-went valve replacement open
heart surgery. In the opinion of my cardiologist warfarin sodium is the ONLY
blood thinning agent which works. Everything else is a waste of money. I
personally don't accept this premise as I don't believe in absolutes. While I am
taking the warfarin presently my goal is to replace this substance with a
natural/organic alternative. This may be a combination of foods and supplements.
The challenge is in finding unbiased research.
There is no simple answer. Some of the supplements listed at the top of this page may be helpful, but we suggest consultation with a health expert familiar with your condition and natural warfarin alternatives.
I use CoQ10 100 mg daily 5 days a week. I have
noticed a lot of improvement in my energy and general condition of my health
despite my age ( I am 76). My wife who is 70 has been using also CoQ10 50 mg
with reasonably fair results. However, a year ago she had a stroke and she had
immediate treatment in hospital, which saved her life. Now she almost recovered.
She has to take every day one tablet of warfarin 3 mg for coagulation purposes
for the stroke together with several other medicines for high blood pressure (Ezetrol,
Exforge, Avernol and flutex) and Crestor for high cholesterol. She was told by
another user of CoQ10 that he had read on some instructions on the CoQ10 package
that if you are treated with warfarin then you should not use CoQ10. Kindly let
me have your view on the matter and in particular if you would also advise that
she should not take CoQ10 together with warfarin.
In a rat study, coenzyme Q10 CoQ10 treatment accelerated metabolism of warfarin which would result in reduced activity. However, a human study did not find coq10 supplements to have an effect on activity.
I was recently put on warfarin (around 6 mg per day) due
to blood clot in a vein in my leg (where I had a cast for broken ankle/leg). My
medical nutritionist put me on Vitalzyme Xe (made by World Nutrition Inc) for
somewhat high fibrinogen levels after I had been diagnosed with uterine
leiomyosarcoma cancer in 2010. (PET/CT recently shows no cancer) The fibrinogen
level went down to 352 a couple months ago. Iím taking 3 Vitalzyme Xe a day even
while now on the blood thinner for past 3 weeks. Should I stop taking Vitalzyme
Xe since Iím now on warfarin?
I have no idea how effective this product is for blood thinning since I have not seen human studies regarding its effect on blood thinning.