title: Effectiveness and safety of a 10mg warfarin initiation nomogram in Asian population.
abstract: Anticoagulant responses to warfarin vary among patients, based on genetic factors, diet, concomitant medications, and disease state. We evaluated the effectiveness and safety of a 10mg warfarin initiation nomogram in an Asian population. Retrospective cross-sectional audit studies were conducted from March 2009 to March 2010. The use of a 10mg-loading dose to initiate warfarin treatment resulted in 33(84.6%) patients attaining a therapeutic INR within four days (mean time, 2.6 days). There was no significant correlation between age, gender, race, and serum albumin for the time to reach a therapeutic INR. A significant correlation was noted for patient's baseline INR and time to reach a therapeutic INR (P<0.05). No significant differences were observed in time to reach a therapeutic INR in patients treated with specific class of concomitant drugs or patients with specific disease states. The overall incidence of over-anticoagulation was 35.9%; however, no bleeding episodes were encountered. In conclusion, the use of a 10mg warfarin nomogram was effective in rapidly achieving a therapeutic INR. However, the nomogram's safety is debatable owing to the high over-anticoagulation rate warfarin-administered patients. Caution is recommended in the initiation of warfarin treatment using the 10mg nomogram.
authors.affiliation: Pharmaceutical Services Division, Ministry of Health Malaysia, Lot 36, Jalan University, Petaling Jaya, Selangor, Malaysia.
authors.forename: Haarathi
authors.initials: H
authors.lastname: Chandriah
authors.affiliation: Faculty of Pharmacy, University Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, Kuala Lumpur, Malaysia.
authors.forename: Endang
authors.initials: E
authors.lastname: Kumolosasi
authors.affiliation: Faculty of Pharmacy, University Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, Kuala Lumpur, Malaysia.
authors.forename: Farida
authors.initials: F
authors.lastname: Islahudin
authors.affiliation: Faculty of Pharmacy, University Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, Kuala Lumpur, Malaysia.
authors.forename: Mohd
authors.initials: M
authors.lastname: Makmor-Bakry
mesh_terms: D000328:Adult; D000368:Aged; D000925:Anticoagulants / Q000008:administration & dosage*; D044466:Asian People; D001281:Atrial Fibrillation / Q000150:complications / Q000188:drug therapy*; D003328:Coronary Thrombosis / Q000188:drug therapy*; D003430:Cross-Sectional Studies; D006801:Humans; D008296:Malaysia; D008297:Male; D008875:Middle Aged; D049451:Nomograms; D011655:Pulmonary Embolism / Q000188:drug therapy*; D012189:Retrospective Studies; D020521:Stroke / Q000188:drug therapy / Q000209:etiology / Q000517:prevention & control*; D020246:Venous Thrombosis / Q000188:drug therapy*; D014859:Warfarin / Q000008:administration & dosage*
chemical_list: D000925:Anticoagulants; D014859:Warfarin