Anticoagulation Services

If you miss your dose of warfarin and realize it before it is time to take your next dose – take it! If it is already time for the next day’s dose, don’t double up and just continue with your usual regimen.

Tylenol® (acetaminophen/APAP) is OK:
Maximum 2000mg per day while taking warfarin
= 4 extra strength (500mg) tablets
= 6-7 regular strength (325mg) tablets
= 4 Vicodin® (hydrocodone/APAP 5/500) tablets

DON’T use NSAIDs (non-steroidal anti-inflammatory drugs) such as: ibuprofen, naproxen, aspirin (unless prescribed by MD), or aspirin-containing products (like Pepto-Bismol® or Alka Selzer®)

Many medicines can interact with warfarin and change your dose requirements. Some of the most common interactions:

• Sulfamethoxazole/Trimethoprim (Septra/Bactrim)
• Metronidazole (Flagyl)
• Erythromycin
• Fluconazole (Diflucan)
• Amiodarone (Pacerone)

Can Cause a Decrease in INR = Raise Warfarin Dose Requirements:

• Dicloxacillin (Dynapen)
• Rifampin
• Carbamazepine (Tegretol)
• Phenobarbitol

Can Increase or Decrease INR:

• Phenytoin (Dilantin)

There are, of course, many more potential interactions… Always call to report newly prescribed medications and supplements to your anticoagulation provider.

Many herbal supplements and alternative medicines are not well studied with respect to interactions with prescription medications. Always check with your provider before starting a new non-prescription item.

From the Coumadin package insert:
Caution should be exercised when botanical medicines are taken with warfarin as few studies exist evaluating the potential for interactions.

• Bromelains, danshen, dong quai, garlic, ginkgo and ginseng are often associated with an increase in the effects of warfarin
• CoQ10 and St John’s wort are often associated with a decrease in the effects of warfarin
• Fish oil/omega 3 fatty acids and vitamin E have been associated with increased bleeding when combined with warfarin
  

There have been numerous case reports of a potential warfarin-cranberry interaction over the last several years. The problem with case reports is that it is difficult to establish a strong cause-effect relationship. If one digs deeper into the details of the case reports, there are often other explanations for the elevation in INR--lack of dietary vitamin K, illness, etc.

For more information, please see " The absence of an interaction between warfarin and cranberry juice: a randomized, double-blind trial." As the title indicates, the study concluded that there was no pharmacokinetic interaction. Additionally, it discusses the various case reports and other studies that have been conducted. The author is Jack Ansell MD--the nation's leading expert on anticoagulation.

As with the Ansell clinical trial, we have not seen this interaction at our Coumadin Clinic. Does that mean it's not possible? Of course not. If there is anything that we've learned, it is that with warfarin, just about anything is possible. An individual can potentially have a genetic variation that makes them more or less sensitive to various foods, drugs, etc.

In general, an interaction between warfarin and cranberry products is NOT expected. What we advise, as with everything, is moderation--have a glass, not a gallon of cranberry juice.

• A vitamin (just like vitamin A, B, C, etc) that is found in all foods and your body even makes some vitamin K on its own. (It is not potassium—this is abbreviated K+).
• Vitamin K is found in large amounts in green leafy vegetables (such as spinach, broccoli and brussel sprouts) and liver meats.
• You do not need to change what you eat:  Just be relatively consistent with foods that contain high amounts of Vitamin K.
• See below for a list of foods that are higher in Vitamin K

1. Prepare for travel ahead of time—make sure you have a sufficient supply of all of your medications for the entire duration of your trip. You can often obtain a “vacation supply” of your medications from the pharmacy.
2. When you travel across time zones, it is often easier to take your warfarin at the same time in the new time zone as the time you usually take your warfarin at home. For example: don’t try and figure out the time difference between San Diego and Paris. If you usually take your warfarin at 8pm here, take it at 8pm in Paris.

“Bridging” is a term that refers to stopping your warfarin (usually for a procedure) and using a different medication (often injectable anticoagulants like heparin or Low Molecular Weight Heparin) to protect you until you are able to resume your warfarin. Your doctor will give you specific stop and start dates for the warfarin and injectable medication.

ALWAYS discuss surgery and procedures with your cardiologist or primary care provider prior to stopping any medicines.