Anticoagulation Clinic: A Safety Net

Oral anticoagulation with Coumadin (warfarin) is becoming more frequent as the US and global population ages and encounters those conditions considered appropriate for anticoagulation therapy.1 Two keys to therapeutic success are education and communication, both of which may be in short supply in a busy clinic or physician's office and which may be shortchanged despite good intentions on the part of both the patient and the physician. While the true incidence of complications from excessive or insufficient warfarin therapy is unknown, it is likely greater in the experience of any one physician or clinic if each physician manages his/her own patients. Complications do occur under the best of circumstances and to those with the best of intentions. The effectiveness and safety of warfarin therapy require maintenance of an international normalized ratio (INR) within a therapeutic range established for a variety of conditions. There are a number of predictors that may trigger a nontherapeutic INR: gender, age, body-mass index, height, weight, ethnicity, tobacco and alcohol abuse, interacting medications, vitamins, herbal supplements, dosage intensity, comorbid conditions, diet, frequency of INR testing and warfarin knowledge, to name a few.2-10

There is growing support for the concept of anticoagulation clinics. 11•¹³ Some early evidence suggests therapeutic INR levels are more consistently obtained in clinics monitored by physicians or allied personnel such as nurses, pharmacists and physicians' assistants11-¹⁶ and through self-testing as an extension of a clinic setting.11-2° Currently, there is no uniform consensus on whether Coumadin or warfarin is the preferred anticoagulant.²¹