title: Warfarin dose requirements in a patient with the CYP2C9*14 allele.
abstract: We describe a 64-year-old male of Indian descent with a history of atrial fibrillation who was started on warfarin after hospital admission for acute stroke. He received genotype-guided warfarin dosing as per the standard-of-care at our hospital, with daily dose recommendations provided by the pharmacogenetics service. Genotyping revealed the rare CYP2C9*1/*14 genotype and warfarin insensitive VKORC1 -1639GG and CYP4F2 433Met/Met genotypes. The patient received an initial warfarin loading dose of 4 mg for 2 days, followed by 2-3 mg/day for the following 11 days. He reached a therapeutic international normalized ratio on day 5, which was maintained over the following week. This report adds to the limited data of the effects of the CYP2C9*14 allele on warfarin dose requirements.
authors: Department of Pharmacy Practice, University of Illinois at Chicago, Chicago, IL 60612-7230, USA.
authors: Yee Ming
authors: YM
authors: Lee
authors: Jessica
authors: J
authors: Eggen
authors: Vinay
authors: V
authors: Soni
authors: Katarzyna
authors: K
authors: Drozda
authors: Edith A
authors: EA
authors: Nutescu
authors: Larisa H
authors: LH
authors: Cavallari
mesh_terms: D000483:Alleles; D001281:Atrial Fibrillation / Q000139:chemically induced / Q000188:drug therapy*; D065729:Cytochrome P-450 CYP2C9 / Q000235:genetics*; D004305:Dose-Response Relationship, Drug; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D020521:Stroke / Q000150:complications / Q000188:drug therapy / Q000473:pathology; D014859:Warfarin / Q000008:administration & dosage* / Q000009:adverse effects
chemical_list: D014859:Warfarin; C450260:CYP2C9 protein, human; D065729:Cytochrome P-450 CYP2C9
keywords: CYP2C9*14; VKORC1; anticoagulation; pharmacogenetics; warfarin