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Deep Vein Thrombosis Health Center

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Taking Blood Thinners for Deep Vein Thrombosis (DVT)

Monitoring Your Blood While on Warfarin for DVT

Taking warfarin for DVT is a balancing act. You want to receive enough warfarin to decrease your risk for blood clots, but not so much that clotting stops completely. If this happens, you're at high risk for bleeding problems. This is why the doctor needs to monitor your blood while you're on this medication.

The test used most often to monitor the effect of warfarin is called prothrombin time (PT). The results of this test determine how high or low your dose of warfarin should be. Your dose may be higher when you first begin treatment, then it may be adjusted to a maintenance level. The doctor may also adjust your warfarin dose in response to your circumstances, such as being scheduled for surgery or needing to take other medications.

Let your doctor know if you're planning to travel. You may need to make arrangements for blood tests right before you leave and while you're away.

Taking Precautions While on Blood Thinners

To prevent bleeding problems, take these precautions while you're on anticoagulants:

  • Don't smoke.
  • Use a soft toothbrush.
  • Floss with waxed floss, instead of unwaxed floss.
  • Instead of a straight or blade razor, use an electric razor.
  • Wear gloves while gardening or doing other household projects.
  • Avoid rough sports, but wear protective gear for activities such as bicycling.

Foods that are rich in vitamin K can make warfarin less effective. Try to avoid large amounts of these foods, but do not suddenly lower your intake without discussing this with your doctor.

  • Beef or pork liver
  • Green tea
  • Alfalfa
  • Asparagus
  • Broccoli
  • Brussels sprouts
  • Cabbage
  • Cauliflower
  • Lettuce, spinach, kale, or turnip greens
  • Watercress
  • Canola and soybean oil

Also, talk with your doctor before taking vitamin E or changing your dose. Vitamin E may increase the impact of warfarin. Avoid alcohol or drink only limited amounts, because alcohol can affect how your body handles warfarin.

Potential Side Effects of Blood Thinners

If you're taking heparin or warfarin for DVT, call your doctor right away if you have any of the following signs or symptoms. Many are signs of excessive bleeding.

  • Red or dark brown urine
  • Red, dark brown, or black stool
  • Periods that are heavier than usual
  • Bleeding gums
  • Nosebleeds
  • Cuts that don't stop bleeding
  • Severe headache or stomach pain or upset
  • Weakness, faintness, or dizziness
  • Frequent bruises or blood blisters
  • Skin rash or irritation
  • Unusual fever
  • Joint or back pain
  • Swelling or pain at an injection site

WebMD Medical Reference

Reviewed by Michael W. Smith, MD on February 09, 2012

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