One of the most confusing problem patients have is how to use blood thinners, how they work and what their risks.  There are basically two types of blood thinners available for home use and a third kind that is only used in the hospital or under special conditions.  The first blood thinner and by far the most important is aspirin.  The blood clotting system of the body has more than 14 known components (proteins) in the blood that act in a sequential manner and result in a blood clot forming.  This blood clotting system is very important when a person gets injured and bleeding needs to be stopped to save the person’s life.  However, in modern society it is very, very rare that anyone “bleeds to death”.  By far the more important problem is a blood clot forming inappropriately inside the blood vessels of the body.  Arteries carry blood to the various parts of the body so that oxygen and nutrients can get to all parts of the body.  If the artery that supplies an area is clogged up with blood clot then that part of the body does not get the necessary blood and it will die.  Common examples of this problem are heart attacks where part of the heart does not get the blood that it needs, strokes where a part of the brain does not get the blood that it needs and gangrene as on the foot, where the foot does not get the blood that it needs.  These problems occur because blood clots form in the arteries over a period of time and then finally shut off the blood supply all together.

     Aspirin is the single most important medication to prevent heart attacks and strokes as well.   Aspirin will decrease the rate of heart attack by at least ½ in the population of people who use this medication. The dose necessary varies.  Eighty percent of the adult population is adequately treated with an 81 mg tablet.  Twenty percent of the adult population need the larger dose of  325 mg (5 grain) standard aspirin tablet in order to be adequately anti-coagulated.  The problem is that we don’t know who’s who and so I recommend that everyone take the large 325 mg tablet of aspirin daily if tolerated.  There is no brand preference although some people think that coated aspirin causes less irritation to the stomach.  It would be unexpected that a person would get significant stomach irritation from only one aspirin per day especially if taken with meals.  The uncoated cheap aspirin is adequate to deal with the heart attacks, strokes and gangrene which occur in the absence of this medication.  In today’s world, it would be recommended that all individuals 50 years of age and older take one aspirin per day assuming that it can be tolerated.  The side effects of aspirin preventing some people from using it include sensitivity with asthma, rare allergic reactions and as mentioned even less rarely stomach problems for a person taking aspirin per day.

     Since aspirin affects platelets and is necessary to stop bleeding when surgery is done, a surgeon will often ask the patient to stop their aspirin one week before anticipating surgery as a precaution.  However, even if surgery is done while the person is taking aspirin, control of bleeding is usually easily achieved and dangerous hemorrhages are not expected.

 Plavix is a newer anti-platelet blood thinner that is used when aspirin is not effective enough.  It is more expensive but seems to be more effective than aspirin.
     A second type of blood thinner used for a variety of clinical problems is Warfarin (Coumadin).  Vitamin K is an essential nutrient required for the liver to make clotting factors for the blood.  Coumadin gets in the way of Vitamin K and prevents clotting factors from being made at the normal rate.  Thus, the concentration of clotting factors in the blood decreases in individuals on Coumadin because the liver makes fewer of certain blood clotting factors.  While this results in blood clotting less rapidly inside the body, it is very rare that it has a dangerous effect allowing the person to bleed excessively.  People frequently notice that they bruise more easily and that small bumps may result in bleeding under the skin but these are not dangerous provided that the medication is adjusted appropriately.

     Coumadin is a much more difficult medication to regulate than aspirin.  Each person seems to react to Coumadin a little bit differently so that the dose for one person is way too much or not nearly enough for another person.  The medication has to be carefully regulated and blood tests have to be done on a frequent basis to insure adequate control and just the right amount of clotting factors in the blood.  Blood tests need to be done no less than every month to six weeks and frequently more often if the medication dosage is being adjusted.  If the dose of medication in the blood becomes substantially diminished, increased bruising and perhaps even significant hemorrhage can occur.  Thus, it is very important that a person monitor the dose of Coumadin in a blood test on a periodic scheduled basis.

     Coumadin as mentioned above has a substantial effect in preventing clotting inside of the body and the blood vessels.  It can be used for a number of different medical conditions including people that have blood clots in their leg veins, people who have blood clots in their lungs, people who have artificial heart valves placed surgically, or people who have had a slight stroke which often comes before a large stroke.  If Coumadin can be started on a person before a major stroke occurs, the major stroke can often be prevented.  An additional very important use for Coumadin is to prevent a stroke in people who have a heart condition called atrial fibrillation.  In atrial fibrillation, blood clots can perform in the heart and break off and go to the brain or other parts of the body with catastrophic results.  This is a preventable problem in people who have atrial fibrillation if Coumadin is used to prevent the blood clots from ever forming in the heart.  Coumadin in addition to aspirin is sometimes used for people who have coronary artery disease when aspirin is not enough to control the condition.

     The side effects of Coumadin are primarily related to regulation of the drug.  When the drug is administered in two large of a dose, a tendency to bleed can occur causing increased bleeding as mentioned or hemorrhages as mentioned.   This is prevented by appropriate visits to your healthcare clinic where your Coumadin dose can be monitored safely.  Rarely, Coumadin can cause an allergic reaction.  Contrary to misunderstandings that the public has, Coumadin does not contribute to a person being cold because their blood is too thin.  Coumadin does not decrease the absolute amount of blood that a person has; it merely decreases the rate at which it clots.

     Pharmacy instructions frequently mention that a person taking Coumadin should not take aspirin.  In fact, Coumadin and aspirin work on two entirely different symptoms in the clotting process.  It is often important that a person be on both medications and when they are appropriately regulated there is little danger from the use of both medications.  The most critical important step is to be sure that the Coumadin dosage is appropriately adjusted by frequent visits to your clinic for monitoring.