Nine-year experience with a pharmacist-managed anticoagulation clinic

A pharmacist-managed anticoagulation clinic is described, and information on patient outcome during a nine-year period is presented. Since 1974, a pharmacist has managed an anticoagulation clinic for ambulatory patients and inpatients at San Francisco General Hospital Medical Center. The pharmacist's primary responsibilities include the following: educating patients about their diseases and the importance of drug therapy, monitoring patients' vital signs, performing physical examinations, and adjusting warfarin dosage to maintain prothrombin times within the therapeutic range (1.7-2.5 times normal using control values of 1.0-1.2). These patients are also under the care of their primary physicians. The pharmacist's work is checked by the chief of the cardiac clinic at the end of each clinic session. The effectiveness of the pharmacist in managing clinic patients is reviewed periodically; from January 1975 through June 1984, the pharmacist had treated 140 patients (141 courses of therapy). Of 1792 prothrombin times taken during this time, 1060 (59.2%) were within the therapeutic range of 17-25 seconds, 510 (28.5%) were less than 17 seconds, and 222 (12.4%) were greater than 25 seconds. Only four major hemorrhagic events (0.002 hemorrhages per patient-treatment month) and 89 minor events (0.05 hemorrhages per patient-treatment month) occurred. The recurrence rate of thromboembolic events was 0.007 per patient-treatment month. Pharmacist-managed warfarin therapy in these clinic patients resulted in a level of anticoagulation control and morbidity that was acceptable to physicians.