A better way to prevent blood clots?

A drug derived from cobra venom offers an alternative to warfarin, although liver problems temper its benefits.

Since the 1950s the drug warfarin has been a key weapon in the battle against blood clots. Millions of Americans take it every day, making it one of the top 10 prescription drugs.

It's also one of the most difficult drugs to use. Some foods block warfarin's anticlotting action. So do a host of prescription and over-the-counter medications, as well as some herbal and dietary supplements. And the same dose of warfarin has different effects on different people.

To continue reading this article, you must login.
  • Research health conditions
  • Check your symptoms
  • Prepare for a doctor's visit or test
  • Find the best treatments and procedures for you
  • Explore options for better nutrition and exercise
Learn more about the many benefits and features of joining Harvard Health Online »