Abstract:
Background: Warfarin is a commonly used oral anticoagulant in clinical practice. Optimal
treatment with warfarin is challenging since it has a narrow therapeutic index. İt is associated
with high frequency of food and drug interactions. Appropriate patient education regarding
warfarin therapy may increase adherence to drug and reduce complications.
Objectives: To assess patient compliance on use of warfarin and the impact of pharmacist initiated educational counseling in improving medication adherence in patients receiving
warfarin.
Methodology: This prospective study enrolled 100 patients who are on warfarin attending
different clinics in a Teaching Hospital. Patients were interviewed using pre-tested ıntervıewer
administered questionnaire at baseline. Patients were randomly allocated to two groups as
intervention and control. The intervention group received educational intervention on
appropriate use of warfarin as per published guidelines using information leaflets and telephone
reminders twice a month. At the end of three months, patients' knowledge in both groups was
assessed using the same questionnaire used at the baseline.
Results: The control group maintained the constant dose level and International Normalized
Ratio (INR) within 2-3 as 14.29% and 26.53%, respectively. In contrast, after education
intervention, 17.39% (17.39-intervention vs 14.29-control, p=0.67, X2=0.18) and 36.96%
(36.96%-intervention vs 26.53-control, p=0.26, X2=1.24) patients in the intervention group
could maintain the constant dose level and INR within 2-3, respectively suggesting slight but
statistically non-significant increase in adherence. All patients preferred information leaflets and
majority (93.47%) to telephone reminders as an effective educational tool to increase the
compliance. Telephone reminders, offering information leaflets and counseling are effective in
enhancing the knowledge regarding dosage regimen, side effects and type of foods to consume,
compliance of patients compared to the control group. Education intervention may also help to
reduce secondary complications such as bleeding, dark purplish mottled fingers and toes, and
allergic reactions from 26.09% to 4.35% in the intervention group (p=0.0023, X2=9.32).
Conclusions: Education intervention in the form of information leaflets and telephone
reminders help to improve compliance of patients and therapeutic outcome of warfarin. Larger
studies are warranted to generalize these findings.
