Anticoagulant medicines are a group of medicines that inhibit blood clotting, helping to prevent blood clots. Blood clots can cause heart attacks and strokes. Common anticoagulant medicines include:
- Coumadin®, Jantoven® (warfarin)
- Lovenox® (enoxaparin)
- Hep-Lock U/P®, Hep-Lock®, HepFlush-10® (heparin)
- Pradaxa (dabigatran)
- Eliquis (apixaban)
- Xarelto (rivaroxaban)
Let’s Focus on Warfarin
While some of the newest oral anticoagulants requires less monitoring, the focus of this page is warfarin, a common anticoagulant medicine. You should speak with your care provider about other options if warfarin is not a good option for you. Warfarin is available in a pill form. The number of milligrams (mgs) is marked on each pill. The pills come in a variety of colors. The colors change based on the brand or generic product and the number of mgs.
When is anticoagulation medicine prescribed?
Anticoagulant medicines can be used with a number of diseases when there is an increased risk of blood clots. Anticoagulant medicine is used to prevent blood clots seen with:
- Atrial fribrillation or irregular, fast heart beat: Atrial fibrillation causes blood to pool in the upper chambers of the heart sometimes. Blood clots may form in the pooled blood.
- Heart valve replacement: Blood clots may form on or near the heart valve.
- Left ventricular dysfunction or cardiomyopathy: Ventricular dysfunctions causes blood to pool in the lower chambers of the heart sometimes. Blood clots may form in the pooled blood.
- Deep vein thrombosis: A blood clot forms in the deep veins of the legs.
- Pulmonary embolus: A blood clot forms and travels to the lungs, often from a deep vein thrombosis.
- Stroke: A stroke may be caused from a blood clot in the brain.
- Transient ischemic attack: TIAs are often early signs of a future stroke.
- After surgery: People are at increased risk for blood clots after surgery.
In each of these situations, and possibly others, warfarin treatment (or another approved therapy) is used for a period of time or a lifetime to prevent blood clots.
How is the dose of warfarin medicine determined?
The amount of medicine in your blood should be monitored closely to assure you are getting enough medicine to prevent blood clots, yet not too much to cause bleeding. Regular visits to the Anticoagulation Clinic are important to monitor your blood levels closely.
When you visit the clinic, the nurse will draw blood with a fingerstick to test your INR (International Normalized Ratio). The INR is a standard measure of the clotting process time. In most situations, the INR level should fall in a target range. If the INR is low there is increased risk of blood clot formation. If the INR is high there is increased risk of bleeding. The Anticoagulation Team will also track your INR results over multiple visits to follow trends in your results. They will look at all this information to determine the dose of medicine you will go home on. The Anticoagulation Team includes a doctor, nurse, pharmacist and lab members.
When do you take the medicine?
You will be taking your medicine as instructed by the Anticoagulation Team. The team often instructs you to take the medicine in the evening before bed. If your dose is changed this will allow time for someone from the Anticoagulation Team to call you with the new dose. This will also help you maintain a consistent blood level and will also help you remember your medicine when taking it at the same time in the evening before bed.
What if you miss a dose?
If you miss a dose take the dose as soon as you remember the same day. If you remember the next day, do not take the missed dose. Just take the regular dose for that day. Inform the nurse at your next INR check thay you missed a dose. If you miss more than one dose please call the Anticoagulation Team. Please call if you have any questions.
What can help you remember to take your medicines?
It may be hard to remember to take your medicine each day. Recognizing this and taking steps to help yourself remember is an important part of managing your anticoagulation treatment. Here are some tips for remembering your anticoagulant medicine each day:
- Develop a daily routine for taking your medicines. Pick something you do every evening before bed (i.e., brushing your teeth, eating a snack, getting your pajamas on) and plan your medicine schedule around that activity.
- Use the Anticoagulation Daily Dose Schedule when you take your medicine. The Anticoagulation Team will give you a copy of the Anticoagulation Daily Dose Schedule. Place the schedule someplace visible to use as a reminder. This is often helpful when you medicine dose is changing or there is added stress in your life.
- Pill boxes can help you remember to take your medicines. By packing a day or a week's worth of medicine you will know if you took your medicine or not. Pack the medicine at the same time each day or week. However, once the medication leaves the original bottle, it loses its identification and instruction label. You may want to have someone double check your pill box to make sure it is packed correctly.
Will the medicine dose change?
The dose of medicine will change at times. The dose of medicine will be based on your INR blood levels, the trend of the blood levels and your symptoms. The Anticoagulation Team will review the medicine dose with you each time you visit the anticoagulation clinic. Remember to ask any questions you have about your treatment.
What about refilling a prescription?
- When you get your medicine, check to make sure the correct number of mgs are listed on the pill. The Warfarin pills come in a variety of colors. The colors change based on the brand or generic product and the number of mgs. Ask the pharmacist filling the prescription to verify you have the correct dose. Also, ask the pharmacist if you notice a problem.
- When you get your medicine you can also make sure the number prescription on the label matches the original prescription.
- Plan to get a new prescription when you pick up your last refill - or sooner. Contact the Anticoagulation Team for a new prescription. An alternative is to contact your pharmacy but this may be a lengthy process.
- Most prescriptions, including refills, are only good for 12 months. At that time, a new prescription is necessary and you must be seen in the anticoagulation clinic.
Can other medicines and foods affect the anticoagulant medicine?
Medications, foods, herbs, vitamins and alcohol can interact with anticoagulation medicine. There are important medicine and diet considerations when taking an anticoagulant medicine. Avoid making any dramatic changes to your diet when taking anticoagulation medication. This may present a challenge when you are travelling or eating out but attempt to maintain a similar diet.
Make sure to contact the Anticoagulation Team with any medicine changes (including over the counter medicine and herbal remedies) or diet changes before making the change.
Learn more about anticoagulant medicines and the potential for drug-food interactions.
Can you exercise while taking anticoagulant medicine?
Discuss any dramatic changes to your exercise program with the Anticoagulation Team before you make the change. The team may recommend you avoid contact sports and exercise that has an increased risk of falling and injury.
What if you become ill while taking anticoagulant medicine?
Let the Anticoagulation Team know if you are sick with a fever, infection, and diarrhea or vomiting. These illnesses can affect the INR level. In addition, antibiotics that may be used with an infection can affect the INR level.
What should you consider when traveling?
Talk with the Anticoagulation Team ahead of time if you are planning to travel. The team may ask you to have an INR blood test done before you travel or sometime during your trip. Consider these measures before and when you travel:
- Make sure you take enough of the anticoagulant medicine for the entire trip.
- Keep the medicine with you during your travels in the labeled prescription bottle.
- Avoid placing medicine in extreme hot or cold temperatures.
- Continue to take the medicine before bed.
- Avoid making any dramatic changes to your diet.
- Know where you can go for healthcare in case of an emergency.
- These measures may be more difficult when you travel since you are out of your normal routine. Plan ahead when you travel!
Can you consider becoming pregnant or breastfeeding while taking anticoagulant medicine?
If you are planning to become pregnant or are pregnant you must contact the Anticoagulation Team right away. There are serious risks to the fetus, especially during the first trimester.
Anticoagulant medicine does not pass into the breast milk, but talk with the Anticoagulation Team before breastfeeding while on anticoagulant medicine.
What if you are having surgery, including dental surgery?
Contact the Anticoagulation Team if you will be having surgery. Also let your surgeon know you are taking an anticoagulant medicine. The Anticoagulation Team will prescribe the appropriate dose of medicine before, during and after the surgery. This is also true if you are having dental surgery.
What can you do if you get a cut?
If you get a cut that is bleeding apply pressure to the cut until the bleeding stops. You may want to have gauze pads available when you apply pressure. This will help the blood clot. If the bleeding does not stop, or the cut is large, get medical help right away. This may include going to the emergency room or calling 911.
If you have a new bruise, apply a cold pack to the bruise. You may want to have cold packs available also.
When do you call your healthcare provider?
The main side effect seen with anticoagulant medicine is bleeding. Bleeding or hemorrhage (bleeding within the body) can occur in any part of the body.
If you notice these signs and symptoms call your healthcare provider right away:
- Dizziness, headache or trouble thinking clearly
- Coughing up blood
- Nausea or vomiting blood or coffee ground looking material
- Swelling, painful or hot joints
- Increased bruising or bleeding
- Blood in the urine
- Bloody or black, tarry stools
- Severe menstrual bleeding
- Feeling very tired or weak
- Nausea and vomiting for more than 24 hours
- Bleeding from the gums after brushing teeth
Also call if you fall or have an accident, especially if you hit your head, even if you feel fine.
Should you wear a medical alert bracelet?
Since there is an increased risk of bleeding it is important for you to wear a medical alert bracelet of some sort. This will alert emergency personnel that you are taking anticoagulant medicine if you are in an emergency situation.
What should you tell family and friends?
Make sure family and close friends are aware you are taking warfarin. Let them know signs of bleeding. They can be helpful when you need emergency treatment.
Anticoagulant medicines can be very helpful when used with a number of diseases when there is an increased risk of blood clots. Please contact your healthcare provider with any questions you have during your treatment.
This information has been approved by Andrew M. Freeman, MD, FACC, FACP (January 2014).