Many dental patients are taking “blood thinner” medications for various medical conditions to prevent the formation of potentially harmful blood clots [e.g: stroke, heart attack, deep vein thrombosis (DVT) or pulmonary embolism (PE)]. However, these medications interfere with the body’s normal clotting mechanism to stop blood flow at a site of tissue injury, which is of concern to dentists for procedures that cause bleeding.
There are two main pathways by which the body normally forms a blood clot. The first involves small blood cells called platelets which clump together at the wound to form a plug which slows the flow of blood through the vessel and forms a matrix. The next phase is coagulation when proteins in the blood interact with each other to fill in the spaces between the platelets, stabilize the clot, and make it more solid until bleeding stops.
Antiplatelet medication [i.e: aspirin, Ticlid (ticlopidine), and Plavix (clopidogrel)] target the first phase of clot formation by preventing platelets from sticking to each other and to the blood vessel walls. Aspirin does this by creating permanent changes in the platelets which last throughout the lifetime of the platelet (7-10 days) which can only be reversed as the body produces new platelets that have not been exposed to the medication.
Anticoagulant medications [i.e: Coumadin (warfarin)] inhibit the second phase of clotting by blocking production or the function of proteins that stabilize the clot (anticoagulation). For warfarin, it takes several days after the starting of medication to reach full anticoagulation effect, and several days after the medication is stopped for the anticoagulation to stop. In addition many foods and other medications can affect warfarin by either increasing or decreasing activity, therefore the physician needs to frequently monitor (with blood test – See Box to right) for too little or too much anticoagulation activity. There are newer anticoagulants such as Pradaxa (dabigatran), Xarelto (rivaroxaban) and Eliquis (apixaban), which do not need as much time as warfarin to reach full anticoagulation effect, and also to stop that effect when discontinued. However, their anticoagulation activity cannot be monitored as easily as warfarin. Lovenox (enoxaparin) is used to prevent PE and DVT, and is given through self-injection.
|Some Dental Procedures
Associated with Bleeding
Dental prophylaxis (teeth cleaning)
Scaling and root planning (deep teeth cleaning)
Periodontal (gum) surgery
Dental implant placement
Preparations for dental procedure
Most of the time bleeding from dental procedures is not difficult to control and stop, even in patients who are taking blood thinners. However, both the effect of these medicines on clotting and the potential for bleeding from dental procedures varies between each patient. Therefore, for each procedure and patient, the risk of bleeding from the dental procedure must be weighed against the risk of harmful blood clot formation from altering the dose or discontinuing the medication.
The INR is shorthand for “International Normalized Ratio.” It is the primary method that health care providers use to measure the degree of anticoagulation for taking Coumadin (warfarin). For most medical conditions, the expected range for anticoagulation as measured by the INR is 2.0 – 3.5. An INR of 2.0 roughly means that a person taking this drug takes twice as long to clot than a normal individual.
Your dentist will want you to provide a thorough and complete medical history. Factors that he/she may ask you to provide include: all medical conditions (e.g: heart disease, irregular heartbeat, stroke, liver disease, kidney disease, history of blood clots); all current medications; name of your physician; purpose of antiplatelet and/or anticoagulation therapy medications; anticipated time that you will be on these medications; the results of any monitoring of the effects of these agents (blood test results); and any problems that you have had with your medicines. Your dentist may run some tests before your treatment and consult with your physician before doing the dental procedure. They may do the dental procedure in one of 3 ways: 1) continue taking the medications as normal; 2) change the dose or type of medications or; 3) stop the medication before the procedure. Furthermore, precautions may be made before, during and after the dental procedure to reduce the risk of significant oral bleeding. Do not discontinue or alter your medications without the advice of your physician and dentist.