Frequently Asked Questions

Those who've been around the wards know that there are a few questions that attendings and residents like to ask students. Before doing a radial arterial line, you will get asked about the Allen's test; when taking care of a patient in diabetic ketoacidosis, you will get asked about treatment of hyperkalemia; when a surgical patient has a fever after an operation, you will get asked how many days post-op he is. But one question that I've been asked twice so far has to do with the origin of the word warfarin, and so here is its fascinating history.

A strange disease struck Cows of Canada in the 1920s. Cows undergoing minor procedures like dehorning and castration were dying from hemorrhage unexpectedly. A Canadian veterinarian investigated these untimely deaths and found that cattle who ate moldy sweet clover were bleeding to death. He determined that the moldy sweet clover had an anticoagulant property. Twenty years later, Karl Link at the University of Wisconsin decided to isolate this compound and after several years and several graduate students, he was successful in extracting the compound. Their characterization of dicoumarol led to development of the anticoagulant warfarin, named after the Wisconsin Alumni Research Foundation which became rich off the patent. Warfarin was widely used as rat poison. In 1951, a U.S. army recruit attempted suicide by ingesting the compound. He was unsuccessful and recovered fully; as a result, warfarin was studied as an anticoagulant in humans. When Dwight Eisenhower had a heart attack in 1955, he was prescribed the drug. Now it is widely used to prevent strokes in patients with atrial fibrillation, artificial heart valves, and other risk factors for clots.

Image of warfarin tablets from Wikipedia, in the public domain.