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Anticoagulation Blood Thinners What's New (Dr Bartholomew 6 27 12)

Wednesday, June 27, 2012 – Noon


Have a question about anticoagulation blood thinners? Section Head of Vascular Medicine, Dr. John Bartholomew helps you sort through all of the information about the different medications and their risks, and answers your questions.

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Cleveland_Clinic_Host: Welcome to our "Anticoagulation Blood Thinners, What's New" online health chat with John Bartholomew, M.D. He will be answering a variety of questions on this topic. We are very excited to have him here today!

Anticoagulants: Warfarin (Coumadin); Dabigatran (Pradaxa); and Rivaroxaban (Xarelto)

Cleveland_Clinic_Host: Welcome Dr. Bartholomew. To start, let's talk a little about the different anticoagulants that people may be asking about today.

Dr__Bartholomew: There are several new drugs available that are aimed at replacing Coumadin or warfarin. These drugs act differently than warfarin. The one advantage is that patient’s blood work does not need to be monitored. In other words, patients do not need an INR on a regular basis. The drugs act differently than warfarin in other ways as well:

  • Dosing adjustments are not necessary making the drugs easier to manage. 
  • They cannot be neutralized or reversed if bleeding becomes an issue. Warfarin can be neutralized by the addition of vitamin K or fresh frozen plasma. 
  • There are several other advantages of the new drugs, including fewer drug-drug interactions and fewer drug-food interactions. Dabigatran (Pradaxa) and Rivaroxaban (Xarelto) are currently used for non-valvular atrial fibrillation and Rivaroxaban is also used for prevention of deep vein thrombosis and pulmonary embolism in patients undergoing hip or knee surgery.
  • These new drugs are more expensive at present.

Pgcorky: Just curious about the new medications vs. warfarin. Are they any better at achieving and maintaining effective levels? In other words, will I still have to get PT/INR done as often?! Ouch!

Dr__Bartholomew: There is no need to monitor your PT/INR on the new medications. In fact, you will not need any blood work except for at the start of the medication to check your kidney function and in some cases liver function as well as a routine blood count (CBC). These drugs are as effective as Coumadin for their current indication.

Cleveland_Clinic_Host: Dr. Bartholomew, who would be a good candidate for the new drugs?

Dr__Bartholomew: Patients that are good candidates for the new drugs are those individuals that have trouble regulating their Coumadin medication (INR); individuals who are on other multiple medications that may interact with Coumadin; and those individuals who may have food interactions with Coumadin. In addition:

  • Patients that live in areas that it is difficult to have their Coumadin monitored may be good candidates for the new medications. Also those individuals who travel extensively and do not have access to laboratories that can monitor their Coumadin may be reasonable candidates. 
  • Patients may want to try the medications who want to feel less tied down to their medications and physicians.
  • Those patients who have lifestyle limitations.


nutzy: there are any trials for Rivaroxaban, Dabigatran or some other knew medicine for people with mechanical valves? I know that some people from this group have problems with keeping the INR between 2.5 and 3.5. Thank you!

Dr__Bartholomew: There are some trials in Europe but these drugs are not yet approved for mechanical heart valves.

naturelover: Are there any anticoagulants expected to be released on the market soon that are safer than Pradaxa (i.e., they can be reversed)?

Dr__Bartholomew: The only other drug that I know of is Apixaban. However the FDA has not released that medication yet and unfortunately it cannot be reversed as well. Therefore the answer to your question is no. However, there is ongoing research to find an antidote and one may be coming soon.

Bruce: What is the status of any studies/trials for use of Pradaxa or similar drug to use on patients w/ artificial heart valve?

Dr__Bartholomew: The data on pradaxa and heart valves is not yet available.

Horstmann: Has any research ever been done regarding Nattokinase as a substitute for current bloodthinners. I frequently read A Fib forums and this supplement is mentioned frequently due to it's affect on fibrins. It sounds promising and many afibbers use Natto. How about fish oil? Just read your response regarding the home monitoring of Coumadin...will have to look into that if I ever have to go back on the drug.

Dr__Bartholomew: I am not aware of any well designed trials using Nattokinase for the prevention or treatment of blood clots or for patients with atrial fibrillation. I know of many patients using this medication but I do not encourage it if they have atrial fibrillation or blood clots based on the lack of trials.

New Medication Safety

AliceS: I had an ablation in April. I have been in A-Fib twice since. I had been on Warfarin since 2005 when I first went into A-Fib and had a TIA. After the recent ablation my INR was fluctuating, and my cardiologist suggested Pradaxa. While on Pradaxa I became anemic and extremely tired. I now am on Xarelto. How safe are these new medications?

Dr__Bartholomew: The medications have been extensively studied. However, if you have bleeding neither of the new medicines can be neutralized or reversed. This is one of the disadvantages of the new medications. I think it is important for you to have a thorough gastrointestinal evaluation to look for the source of your bleeding. You can also bleed on warfarin as well. The drugs have been proven safe however otherwise they would not be on the market.


TomG: Dr. Bartholomew: I have been taking Coumadin for about 5 years before & after successful single bypass & maze procedure for Atrial Fib. No problems with AF for 3+ years. What are the long term effects of continuing this medication? I am 69 years old. Could I get off Coumadin since I have had no recurrence of AF? Could an evaluation of an electrophysiologist @ CC be able to help me out?

Dr__Bartholomew: Many patients are on life-long Coumadin and have no side effects. The major side effect of course is bleeding. I suggest you discuss stopping Coumadin with your electrophysiologist as you have mentioned. However, as mentioned above, many many patients take Coumadin life-long.

scottie: Is there an ideal time to take Coumadin in the day which maximizes absorption?

Dr__Bartholomew: I always recommend patients take their Coumadin at 5 - 6 pm daily.

scottie: Is that before or after eating? Does it make a difference to absorption to take on an empty stomach?

Dr__Bartholomew: I usually recommend you take Coumadin before eating.

Bruce: I am going to have a small exterior cyst cut out; can I stay on Coumadin for a small procedure like that?

Dr__Bartholomew: You should discuss this with your doctor who may or may not feel comfortable with Coumadin. There are many procedures that can be done on Coumadin such as cataracts and tooth extraction. However, this varies from doctor to doctor and therefore I would call your physician.

It also depends on the reason you are on Coumadin. Some patients can stop this for several days without problems whereas others may need to be bridged with a drug such as low molecular weight heparin to be certain they do not have clotting problems.

Dabigatran (Pradaxa)

F94jL63: I've been taking Pradaxa for three months. Scrapes and scratches from routine chores, gardening, and so on seem to clot as readily as before. Without blood testing how does one know effectiveness of Pradaxa?

Dr__Bartholomew: There is a blood test that one can perform to see if your blood is thinned or not. That test is a thrombin time but it is not routinely used. It simply tells you if your blood is thin. To date, there are no tests that are used to monitor Pradaxa.

F94jL63: Pradaxa's "No Known Antidote" caution is rather disconcerting. What interventions are available in the case of serious injury with bleeding?

Dr__Bartholomew: Obviously the first thing to do is stop the medication. If the bleeding is serious you will be hospitalized and your doctors will keep you well hydrated with intravenous fluids and possibly blood transfusions. If your bleeding is life threatening, some authorities have tried dialysis and/or the addition of a product known as Novo Factor VII.

Rivaroxaban (Xarelto)


Dr__Bartholomew: The prescribing information suggests precaution be taken when using diltiazem with xarelto. I suggest you contact the doctor who has prescribed this and mention your concerns.


annblank: I'm using Lovenox. Do blood thinners have to be injected?

Dr__Bartholomew: Not all blood thinners have to be injected. I do not know your particular situation but there are oral medications including warfarin (Coumadin), Xarelto and Pradaxa. These latter two medications have limited indications, mainly non-valvular atrial fibrillation and for xarelto also DVT prophylaxis for hip and knee surgery. You should contact your doctor about your question - are there other blood thinner medications?

annblank: I inject Lovenox daily to eliminate blood clots and pulmonary embolisms, caused by my cancer. Does Lovenox contribute to my anemia, and any blood thinners that can be administered more easily than injections?

Dr__Bartholomew: The current American College of Chest Physicians guidelines recommend Lovenox or an equivalent low molecular weight heparin preparation such as fragmin be used in patients with cancer and blood clots. The guidelines suggest a minimum of three months with these low molecular weight heparin preparations and many feel a longer time period. Some patients are switched to Coumadin after the 3 to 6 month period if their cancer is under control. The lovenox can contribute to your anemia if you are bleeding but I suggest you discuss this with your oncologist.


icycleoc: I had a Xience V stent installed on 2/16/2011. I am still on a daily regimen of 75mg Plavix and 81mg aspirin. Is it still necessary 16.5 months later to still be on this regimen? I have read that the normal for Xience V stents is 3 to 12 months.

Dr. Ellis (Section Head of Invasive/Interventional Cardiology): The duration of Plavix after this stent seems somewhat debated. Plavix is recommended for 3 months only in Europe. Most doctors in the United States recommend 12 months. However, there may be other reasons that your physician has kept you on Plavix. Perhaps your blockage (lesion) was in a critical location such as the proximal LAD or left main arteries. You should discuss your concerns with your physician

icycleoc: How long does it take for blood to return to its normal state after stopping Plavix?

Dr__Bartholomew: For patients that are on Plavix that need surgery or a procedure the general rule of thumb is to stop this medication 7 - 10 days before any intervention.


F94jL63: Studies and statistics can be difficult to interpret. Last month, the New England Journal of Medicine published findings from the WARCEF study which seem to suggest little difference in risk/benefit between warfarin and aspirin for patients with heart failure. For individuals with Atrial Fib, would aspirin be significantly less effective that Coumadin or Pradaxa - especially in light of the bleeding risks of these latter meds?

Dr__Bartholomew: Using aspirin over Coumadin or pradaxa would depend on your CHADS score. Not all patients with atrial fibrillation are given Coumadin or pradaxa. I suggest you discuss this with your doctor. Please note, there are also bleeding risks with aspirin such as gastrointestinal bleeding.

Food and Anticoagulants

scottie: Can carrot juice (Vit A) affect INR levels?

Dr__Bartholomew: Any medication or food can interact with Coumadin. I am not aware of a major interaction with Carrots or carrot juice. If you take this in excess, however, you may want to have your INR checked to make sure there is no interaction.

Bruce: Where can I obtain a comprehensive list of the various foods that affect anti-coagulant effect of Coumadin?

Dr__Bartholomew: Understanding Coumadin on our website. Here are additional sources of information:


Horstmann: Have low CHADS score, 70 years old, on one regular aspirin per day. Is aspirin protocol still adequate for me? I take two baby aspirin. in the morning and two in the evening.

Dr__Bartholomew: If your CHADS score is low, many physicians use aspirin. Normally patients would take one aspirin per day. I suggest you discuss this with your cardiologist to be certain your CHADS score is low enough for aspirin.

naturelover: What is a CHADS score? I am a 57 year old female, athletic and in good health other than well-controlled A-fib (on Propafenone). My only other risk factor for stroke is a prothrombin mutation. I would love to be on aspirin rather than Pradaxa -- just for safety reasons.

Dr__Bartholomew: The CHADS score stands for (C) congestive heart failure, (H) hypertension, (A) age, (D) diabetes, (S) prior stroke or TIA. You are in good health but have the prothrombin mutation. I would not put you on Pradaxa for the prothrombin gene mutation unless you had a previous blood clot. I would use Pradaxa over aspirin depending on your CHADS score. I suggest you discuss this with your doctor who prescribed the Pradaxa.

Home INR Monitoring

Cleveland_Clinic_Host: We often get questions about home INR monitoring, could you please talk more about that?

Dr__Bartholomew: Most insurance companies, including Medicare will pay for home monitoring of your Coumadin therapy. This makes it easier to stay on Coumadin because it is more convenient. Patients do not have to go to the lab to have their blood drawn. Rather they can do it at home at their own convenience.

It is important if you do decide to go the home monitoring route that you discuss this with your physician and let your doctor know your INR results on a regular basis. Patients who are good candidates for this are patients who are reliable and take their medications as directed.

Anticoagulation or Coumadin Clinics

Cleveland_Clinic_Host: Dr. Bartholomew, you are the director of the Coumadin Clinic or Anticoagulation clinic, what are the benefits of that?

Dr__Bartholomew: The advantages of a Coumadin Clinic include well trained personnel that are experienced in managing this medication. These individuals know drug - drug and drug - food interactions and are experts in adjusting your dose. It is well known that individuals who monitor Coumadin regularly in clinics such as these are much better at keeping their patients within a therapeutic range as compared to the average doctor who may only treat a few patients at a time with Coumadin.

Reviewed: 06/12

This information is provided by Cleveland Clinic as a convenience service only and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. Please remember that this information, in the absence of a visit with a health care professional, must be considered as an educational service only and is not designed to replace a physician's independent judgment about the appropriateness or risks of a procedure for a given patient. The views and opinions expressed by an individual in this forum are not necessarily the views of the Cleveland Clinic institution or other Cleveland Clinic physicians.

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