Chronically anticoagulated patients taking the drug Warfarin require time intensive management and followup processes to avoid complications. The "Chronic Anticoagulation Clinic" (CAC) protocol is a set of production rules that help manage, treat, and follow-up such patients. The CAC protocol has been in regular use at Intermountain Healthcare (Salt Lake City, UT, USA) for over three years. The results demonstrate an improvement on the number of patients with anticoagulation levels within the desired target range. The protocol alerts have a high acceptance rate (83.4%) and were able to help patients remember to collect their next coagulation test. The CAC protocol results show that production rules can improve the management of chronically anticoagulated patients. Additional studies are required to verify if this experience can be transferred to other institutions.