Retrospective Study of Adverse Drug Reactions from Warfarin at Srinagarind Hospital, Khon Kaen Province(Thai)

Abstract

Warfarin is an anticoagulant which has a high incidence of adverse drug reactions (ADRs), especially bleeding complications leading to death. The purposes of this study were to determine frequency, characteristics and severity of ADRs from warfarin and to identify factors associated with the occurrence of detected ADRs. The study was performed retrospectively. Data were obtained from medical records in hospitalized patients receiving warfarin at Srinagarind hospital, Khon Kaen Province over a 1-year period. Of the total 193 patients recruited, 23.3% experienced ADR (n=45) accounting for 50 ADRs. The majority of patients were aged above 60 (31.1%) and diagnosed as mitral stenosis (37.8%) with more than 10 concomitant drugs taken (28.9%). The most frequently detected ADR was prolonged prothrombin time (PT) / International Normalized Ratio (INR) (15.6%), followed by bleeding complications including unspecified bleeding, bruising, hematoma and hemoptysis (7.8%). Most of the ADRs were rated as mild in severity (55.6%). There was no statistically significant association between any factor and the occurrence of ADRs (P> 0.05). In addition, it was found that 9.8% of patients were admitted to the hospital as a result of warfarin adverse effects. Thus, health professionals should play a significant role in monitoring patients receiving warfain therapy in order to prevent and solve ADRs and to diminish the incidence of ADRs from warfarin.