Are Patients on Oral Anticoagulation Therapy Aware of its Effects? A Cross-sectional Study from Karachi, Pakistan

Objective: Oral anticoagulants are one of the most frequently used medications. However, these drugs have a range of side effects including potential life-threatening complications. Little is known regarding the awareness of its side effect profile amongst the patients in Pakistan. Therefore, the aim of this study was to assess the knowledge of oral anticoagulant therapy and its side effects among its users. Results: The mean age was 48.9 ± 15.2 years. Mean scores of the participants for knowledge regarding oral anticoagulants and knowledge specific to warfarin were 49.9 ± 16.2% and 14.6 ± 16.4% respectively. Most notably, the majority of the patients (65.7%) did not know what side effects to be wary of or how to reduce their occurrence; and most of them were unaware of the interaction between oral anticoagulant drugs and over-the-counter substances such as aspirin, herbal medicines and alcohol. Knowledge of International Normalised Ratio (INR) was extremely poor with more than 75% of the population not being aware of the target INR range during warfarin therapy. Higher level of education was significantly associated with better knowledge scores. On the whole, knowledge of oral anticoagulant therapy and INR monitoring is extremely poor among oral anticoagulant users.