warfarinfo

Does warfarin cause weight gain? Probably not by itself. However, when people are started on warfarin they are not feeling well. If they are less active and continue to eat the same, they will gain weight.

Do you have to avoid bright sunlight while on warfarin? I am not aware of any problems. I live at almost 5,000 feet elevation in one of the sunniest places in the United States and have seen no problems.

Can warfarin cause anemia? Anemia means that there is less iron in the blood than normal. Warfarin slows the ability of the blood to clot. If there is a bleeding site somewhere in the body, warfarin will help keep the bleeding going. Warfarin does not cause iron loss by itself. But it will enhance blood loss from any bleeding site.

Is it safe to take iron pills (ferrous sulfate) while on warfarin? After reviewing several references, no interactions were found between warfarin and ferrous sulfate. None of the references indicated that these two drugs cannot be consumed together. Ferrous sulfate is used in the prevention and treatment of iron deficiency anemias. It replaces iron and allows the transportation of oxygen via hemoglobin. Iron does not appear to have any effects on clotting factors—it does not interfere with the coagulation process. Based on the available information, it would be safe to take both ferrous sulfate and warfarin. However, you should notify your physician before taking ferrous sulfate. It would be best to discuss this issue with your doctor since he/she may have further recommendations regarding your drug therapy.

Is it okay to take multivitamins with warfarin? It would be okay for you to take a multivitamin while on warfarin. However, you should choose one that does not contain vitamin K, such as One-A-Day and Shaklee Formula 1. Warfarin interferes with the liver synthesis of vitamin K dependent clotting factors (II, VII, IX, X) and causes the blood to become "thinner." This makes the International Normalized Ratio (INR) increase and puts the patient at risk for bleeding problems. Vitamin K promotes the liver synthesis of clotting factors and increases the coagulation effects of the blood. This causes the INR to decrease and makes the blood "thicker," putting the patient at risk for forming blood clots. Vitamin K antagonizes the effects of warfarin, which leads to decreased anticoagulation. Multivitamins that contain vitamin K should be avoided due to the interaction with warfarin. It is very important to contact your physician before starting or stopping vitamins that contain vitamin K so that the warfarin dosage can be adjusted according to the INR values. The best recommendation would be to take a multivitamin that does not contain any vitamin K.

Where can I send to get educational materials about warfarin? DuPont, the manufacturers of Coumadin have items available. Call 1-800-COUMADIN. Barr Labs, one of the generic warfarin manufacturers has items available at 1-888-WARFARIN.

Can a high INR cause seizures? No. However, a high INR while taking medication for seizure control (particularly phenytoin and carbamazepine) may be a clue that an interaction is taking place between warfarin and the seizure medication. The blood level of the anticonvulsants should be checked also.

Does warfarin make me feel cold? No. Even though it is called a blood thinner, it does not thin the blood. It only slows the ability of the blood to form a clot. The blood circulating in your arteries and veins is no thicker or thinner than it would be if you were not taking warfarin.

Do people ever get off warfarin? Yes, the majority of them will. If the condition requiring warfarin is resolved, then warfarin is no longer needed. For instance, after several month to one year after a first blood clot in the leg, warfarin can be stopped. If the heart returns to the normal rhythm, warfarin can be stopped.

Does warfarin make me feel weak? Probably not. The weakness is more likely the result of the condition that causes you to need warfarin.

What factors can make the INR go up? Starting an interacting drug. Stopping an interacting drug. Stopping vitamins which contain vitamin K. Change in eating habits (less green vegetables). Stopping things like Ensure, Boost, Resource, Carnation Instant Breakfast etc which contain vitamin K. Stopping chewing tobacco (tobacco is a green, leafy vegetable). Change in exercise levels (if you become ill, have surgery etc you do not get your heart rate up to its previous levels. Since warfarin is only metabolized when the blood carrying it passes through the liver, a lower heart rate means less warfarin metabolism. This is like increasing the dose.) A great del of swelling in the legs. ( When there is fluid retention, the liver also becomes congested and blood does not flow through it very well. If a "water pill" is given, the INR can suddenly decrease quite a bit).

Why do I have to take Lovenox (enoxaparin) or heparin and warfarin? Lovenox (low molecular weight heparin) blocks the action some of the factors in the blood which causeclots. It works very rapidly. However, as you know, it must be given by injection. Coumadin (warfarin) slows the body's production of some of the factors which the body make to produce clots. Because these factors are already in the body, you need Lovenox to prevent them from making the clot bigger right away. But you don't want to gets shots every day - forever. So the Coumadin is given, but since it does not act on those factors already in the blood (it only slows the body from making more) it takes a few days to work. That is why you overlap Lovenox (quick) with warfarin (slow).

Can I print out your pages? Any page on www.warfarinfo.com can be copied by simply using the print command. Please not that they are copyrighted, so do not change then in any way.

The warfarin is usually stopped about 4 days before surgery and that same day or the next day low molecular weight heparin (LMWH) is started by injection. This is continued until the last dose which would be scheduled before surgery is due. That dose is skipped. The surgery is done. After surgery, usually even that same night, the warfarin and LMWH are restarted. The LMWH is continued until the INR is once again therapeutic. LMWH works quickly to protect against blood clots. But, it must be given 1 or 2 times daily (depending on the brand) and by injection in the abdomen. So it is a useful short-term alternative to warfarin which takes about three days to reach its full effect again.

Where can I surf to find medical journal articles about warfarin? Try http://www.ncbi.nlm.nih.gov/PubMed/ this gets you to the National
Library of Medicine. If you have to register, do so -- it is free. This
will show you abstracts of medical journal articles. You can also find
related articles. If you want to read the entire article, print the
abstract and take it to a library and see if they can get a copy free on
interlibrary loan.

Is there any information on possible interactions between warfarin and fish oil? Very little information is available about possible interactions between fish oil and warfarin. Since fish oil has mild blood thinning effects, most sources state that it should not be used with warfarin unless told to do so by a physician. Fish oil does not cause bleeding problems when used alone. However, the risk of bleeding is increased when fish oil and warfarin are consumed together. One reference (Bender et al, 1998) mentioned that a double-blind, placebo-controlled study was done to observe the effects of warfarin and fish oil. There was no significant change in the International Normalized Ration (INR), but the trial only included 11 subjects. The conclusion of the trial was that no additional anticoagulation effects were seen when fish oil was given with warfarin. Because fish oil is normally consumed in the diet (omega-3 fatty acids), it is not necessary to take fish oil supplements. The best advice would be to contact your physician and discuss the concomitant use of warfarin and fish oil. The use of both of these may increase the risk of bleeding due to additive anticoagulation effects.

Bender NK, Kraynak MA, Chiquette E, et al. Effects of marine fish oils on the anticoagulation status of patients receiving chronic warfarin therapy. Journal of Thrombosis and Thrombolysis. 1998; 5:257-261.

Fish oil supplementation does not increase bleeding tendency
OSLO, NORWAY. A group of Norwegian medical researchers reports that fish oil supplementation does not increase the bleeding tendency in heart disease patients receiving aspirin or warfarin. The study involved 511 patients who had undergone coronary artery bypass surgery. On the second day after the operation half the patients were assigned in a random fashion to receive 4 grams of fish oil per day (providing 2 g/day of eicosapentaenoic acid, 1.3 g/day of docosahexaenoic acid, and 14.8 mg/day of vitamin E). At the same time the patients were also randomized to receive either 300 mg of aspirin per day or warfarin aimed at achieving an INR of 2.5-4.2. The patients were evaluated every 3 months and questioned about bleeding episodes for the duration of the 9-month study.

The researchers concluded that fish oil supplementation did not result in a statistically significant increase in bleeding episodes in either the aspirin group or in the warfarin group. They also found no significant long-term effects of fish oil on common parameters of coagulation and fibrinolysis. They noted that the blood levels (serum phospholipid levels) of eicosapentaenoic acid and docosahexaenoic acid increased by 140% and 14% respectively in the patients taking fish oil. The serum triglyceride levels decreased by 19.1% in the fish oil group while no significant change was observed in the remainder of the patients. NOTE: This study was partially funded by Pronova Biocare AS (a fish oil manufacturer) and Nycomed Pharma AS.
Eritsland, J., et al. Long-term effects of n-3 polyunsaturated fatty acids on haemostatic variables and bleeding episodes in patients with coronary artery disease. Blood Coagulation and Fibrinolysis, Vol. 6, 1995, pp. 17-22

Can I get a tattoo while taking warfarin? I checked with John Partlow of Dragon's Lair in Pueblo, Colorado. His answer was that he would not do one on someone taking warfarin. The decreased clotting ability of the blood will cause the ink to smudge. You will wind up with one of those tattoos that looks like a sailor got during World War II. One netizen wrote that she got them when her INR was below 2.0. An INR below 2.0 is essentially the same thing as taking no warfarin -- you have little or no protection from a clot -- your blood clotting ability is about the same as normal.