A good friend of mind had a serious heart attack several years ago. He survived but was left with congestive heart failure. His heart was not pumping adequately, and there was a risk of it throwing off clots — clots that could lodge in his heart or brain.

As a protective measure, he began taking blood thinners. Thinners, however, are a double-edged sword. They keep the blood from clotting, but as they do, they allow for the possibility of blood leaking into places it shouldn’t. If all goes well, you count yourself lucky. In my friend’s case, the drugs kept him in reasonably good health until, out of nowhere, the thin blood leaked and he ended up in the hospital with a hematoma — bleeding in the brain. Fortunately it was a minor head bleed, not a stroke. A study from Vanderbilt University Medical Center in Nashville, published last spring in the Archives of Surgery, underscored the dangers blood thinners carry, when it found that people on the popular anticoagulant warfarin(Coumadin) who sustained a traumatic injury (and this can be something as simple as falling in your bathtub and hitting your head) were twice as likely to die as those not on the drug.

DIFFERENT MEDS, DIFFERENT RISKS

What can you do to best protect yourself? To discuss the dilemma, I called Emile Mohler, MD, director of vascular medicine at the Penn Heart and Vascular Center in Philadelphia. Dr. Mohler said that even people who take these drugs can get confused about the exact nature of the medicine they are on. In fact, calling the drugs “blood thinners” is technically incorrect — the drugs do not thin blood but rather act on clots that can form in the blood. And, while the group of drugs overall is referred to as “anticoagulants,” this too is actually not quite correct since different drugs act in different ways. Here is an explanation of the drug categories and how they differ…

  • Anticoagulants — e.g., warfarin (Coumadin). These do not dissolve clots but inhibit clot production and prevent clots from enlarging. They are used for atrial fibrillation, an erratic heartbeat that can create clots that travel to the brain, triggering stroke, as well as for other situations in which clots may form in the heart, such as during heart-valve replacement. These drugs treat blood clots in a deep vein, usually in the legs. This condition is known as deep vein thrombosis (DVT). Anticoagulants also help prevent second strokes or heart attacks.
  • Antiplatelets — e.g., aspirin, clopidogrel (Plavix). Platelets are cells in the blood that form clots to repair damaged blood vessels. Unfortunately platelets also can create harmful clots — and so antiplatelet drugs are used to prevent the kind of platelet “clumping” that starts a clot. Antiplatelets are used for heart attacks caused by a clot (myocardial infarction), for angioplasty/stent patients and to prevent future heart attacks in patients who have already suffered one.
  • Thrombin inhibitors — e.g., heparin. These are fast-acting drugs that are used, usually on a short-term basis, right after many types of surgery to prevent clot formation or to treat patients with vein clots.

Your Safety on Anticoagulants

Dr. Mohler describes these drugs as “incredibly lifesaving,” noting that most of the time the drugs’ benefits outweigh their risks. Nevertheless, he says it is indeed a tough balance between clot protection and bleeding. “There is always going to be a risk of bleeding whatever the specific drug, because otherwise it would mean the drug isn’t effective,” he explains. To maximize your safety, Dr. Mohler offered the following information and advice…

  • Although Coumadin is the most widely used anticoagulant, it is a difficult drug for both patients and doctors, says Dr. Mohler, because “however carefully blood levels are monitored, they can change quickly, and the foods you eat impact your blood levels as well.” For your safety: Strictly adhere to a schedule of monitoring with International Normalized Ratio (INR) blood tests (through a Coumadin clinic) to be sure that your blood levels remain in the proper range. Diet is critical — Coumadin blocks the clotting action of vitamin K, but if you eat foods that are high in K (leafy greens, especially spinach and kale), it can negate the effect of the Coumadin. Limit yourself to the number of servings per week that your doctor advises.
  • Patients on low-dose aspirin therapy must be careful when taking additional aspirin for painkilling purposes, as it can jeopardize the antiplatelet effect. For your safety: Never take additional aspirin. If you need a painkiller, take acetaminophen instead — or if you take ibuprofen, which is more similar to aspirin, always take the additional painkiller at least 30 minutes after taking the daily aspirin to be sure that the other drug will not interfere with the antiplatelet action of the aspirin.
  • Surgery patients need to clot in order to heal, but when taking blood thinners it is tricky, Dr. Mohler says. Depending on the level of clot risk, there are a variety of ways for doctors to handle this problem, including using heparin in place of warfarin for a few days. For your safety: Before surgery, discuss with your doctor how this will be handled to best protect you.
  • Accidents that healthy people are likely to recover from quickly can cause deep bruises and bleeding when a patient is on these drugs. For your safety: Avoid situations with a high risk for injury — even minor injury — such as rough sports, difficult hiking, etc. Always carry a card or wear a medical ID bracelet that lets emergency medical professionals know you are on an anticoagulant or antiplatelet… be sure to inform all of your health-care professionals, including pharmacists, about your drug.

Brighter Days Ahead

There are hopeful developments in the world of anticoagulants with new drugs in development. One called dabigatran (Pradaxa) is already available and may one day replace Coumadin. It is easier to monitor, and diet does not interfere with it. However, you need to take it twice a day, and the drug is very expensive. Another group of anticoagulants called factor Xa inhibitorsis in development, and Dr. Mohler says these too may replace Coumadin in some instances, especially for DVT. Perhaps most intriguing of all, there is a new study underway at The University of Pennsylvania that should make treatment easier and safer. Researchers are investigating patients’ DNA for mutations that affect blood clotting. The hope is that with information specific to individuals, doctors will be able to adjust drug dosages to create optimal levels in each person’s blood.