Abstract:
To determine whether having a pharmacist in providing warfarin monitoring service in prosthetic heart valve patients would be differ in achieving the optimal intensity of anticoagulation as expressed in term of the International Normalized Ratio (the INR) between 2-2.5 (Rajvithi Hospital's recommendation) as well as to compare the primary outcome events; episodes of thromboembolism or bleeding. Data were collected on all patients with mechanical heart valves who have seen at heart surgery clinic at Rajvithi Hospital during December 1996 to October 1997. All patients were randomly assigned into 2 groups, the control group with the existing clinic service and the study group with adding pharmacy educating and monitoring services. 21 patients were lost follow up. The two patient groups, 74 in the study group and 71 in the control group, were followed up for 3 consecutive clinic visits. The result showed that the number of patients with optimal INR of 2-2.5 were not statistically difference in both groups in each follow up visits; 14 (18.9%), 17 (23.6%) and 13 (19.4%) respectively in study group and 8 (11.3%), 14 (22.2%) and 15 (28.3%) respectively in control group. More than 50% of patients in both groups have suboptimal INR. 2 episodes of thromboembolism (TIA) were reported in the study group and none in the control group (not statistically significant). During 3 follow up visits only minor bleeding events were reported in both groups, where in the study group more episodes were detected and reported by pharmacist in each clinic visits (4, 5, and 12 respectively in the study groups and 1, 1 and 1 respectively in the control groups). Furthermore, more drug related problems; those were non-compliance, drug interactions and medication errors, were identified in the study group. With the minimum number of patients that could be follow up in 1 year, this study can not prove the effectiveness in controlling optimal INR in patients with prosthetic heart valve by adding pharmacy's monitoring and educating service but showed the ability of the pharmacist in identifying drug related problems as well as educating the patient in using warfarin appropriately.