Warfarin sodium is the sodium salt of 3-(alpha-acetonylbenzyl)-4-hydroxycoumarin), a compound that thins the blood and was originally used as rat poison. Warfarin treatment reduces the risk of thrombosis (blood clots), but makes patients more liable to bleeding and warfarin 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. Warfarin is the generic form, and it is also sold under the brand name Coumadin by Bristol-Myers Squibb .

Natural supplements and warfarin interactions
Certain supplements have blood thinning potential and should be used with caution by those who are on blood thinning medication such as warfarin. 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.
CoQ10 supplement has been associated with an increased risk of bleeding with the use of warfarin medication.
Dong quai herb is a Chinese herbal supplement which has natural coumarin derivatives.
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 warfarin.
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
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.
Onion
St. John's wort may increase the risk for bleeding when used together with warfarin medication.
White willow bark supplement
     This is a partial list.

Warfarin and Ginkgo Biloba
Ginkgo biloba extract 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. Therefore, in vitro and in vivo inhibition studies were done to ascertain the influence of ginkgo on CYP2C9, the P-450 isozyme responsible for the metabolism of the most potent warfarin enantiomer, (S)-warfarin. Ginkgo extract inhibited human liver microsomal CYP2C9. Two open-label, crossover pharmacokinetic studies in healthy subjects were performed using tolbutamide and diclofenac as probe CYP2C9 substrates. In contrast to the in vitro inhibition of CYP2C9, no interactions between Ginkgo biloba extract and CYP2C9 probe substrates were observed in vivo as evidenced by the lack of effect on the steady-state pharmacokinetics of diclofenac or on the urinary metabolic ratio of tolbutamide.

Chamomile and warfarin
People taking warfarin to prevent blood clots may need to stay away from chamomile products, 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. Warfarin is derived from coumarin -- a naturally occurring chemical compound with anti-clotting properties found in many plants, including chamomile. It's believed that the chamomile tea and lotion acted in concert with the warfarin in this case to cause bleeding. 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, April 25, 2006.

Warfarin bleeding risk
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 - warfarin coumadin
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.

Warfarin side effects - Osteoporosis
The long-term use of warfarin, a drug commonly prescribed to reduce the risk of blood clots, 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. SOURCE: Archives of Internal Medicine, January 23, 2006.

Warfarin genetic test
In September of 2007, the U.S. Food and Drug Administration approved a genetic test to help identify patients at risk of excessive bleeding from warfarin. This test, made by Nanosphere Inc, determines which patients metabolize warfarin differently than expected, and therefore have an increased bleeding risk. The test detects gene variants linked with the increased sensitivity to the drug.

Warfarin diet
The effect of warfarin decreases after initiation of a high-protein, low-carbohydrate diet.

Warfarin alcohol
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 warfarin 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.

Warfarin therapy
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.

Warfarin and Self-Monitoring
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 Hemorrhage Cases
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.

Warfarin 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 warfarin for 3 months and wish to resume taking Lipoic Acid.
   A. We have not come across such interaction between warfarin and lipoic 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 (coumadin)? I take warfarin 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 serrapeptase?
   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. I am a 55 year old female who cannot take hormones due to blood clots. I am on Warfarin for life. Is Passion Rx okay to take with Warfarin ?
    A. We don't recommend Passion Rx to be used by those with cardiovascular conditions, and we don't know how it interacts with warfarin, so to be cautious we suggest not using Passion Rx.

Q. Can warfarin be taken the same day as an ahcc supplement?
   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.

Q. 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.
   A. There is no simple answer. Some of the supplements listed at the top of this warfarin page may be helpful, but we suggest consultation with a health expert familiar with your condition and natural warfarin alternatives.