Respuesta terapéutica inadecuada a la warfarina en un paciente genéticamente susceptible

Víctor Raggio; Pablo Neira; Patricia Esperón; Mariana Lorenzo; Mario Stoll

Authors

Víctor Raggio Universidad de la República, Facultad de Medicina, Hospital de Clínicas, Departamento de Genética, Prof. Adj. Comisión Honoraria para la Salud Cardiovascular, Policlínica de Genética Cardiovascular, Médico Área Genética Molecular
Pablo Neira Médico Emergencista, ARM San Ramón
Patricia Esperón Comisión Honoraria para la Salud Cardiovascular, Área Genética Molecular, Directora Laboratorio. Universidad de la República, Facultad de Medicina, Cátedra Biología Molecular, Prof. Adj.
Mariana Lorenzo Comisión Honoraria para la Salud Cardiovascular, Área Genética Molecular, Colaboradora Honoraria. Estudiante de Medicina
Mario Stoll Comisión Honoraria para la Salud Cardiovascular, Área Genética Molecular, Coordinador. Universidad de la República, Facultad de Medicina, Hospital de Clínicas, Policlínica de Genética Cardiovascular

Keywords:

WARFARINA, PHARMACOGENETICS

Abstract

Warfarin is one of the most used oral anticoagulant whose dosage needs a serologic assessment (INR: International Normalized Ratio) due to its narrow therapeutic range and the virtually severe secondary effects. The main metabolizer of warfarin is the codified enzime for CYP2C9 gene. There are two variants of this gene, relatively frequent, that determine a ‘poor metabolizer’ phenotype. Carriers of these variant alleles are at higher risk of bleeding during oral anticoagulation and need low warfarin doses to reach anticoagulation. A clinical case of a patient under prolilactic warfarin treatment who presented a peek increase of INR and an hematuria episode is reported. The genotype of the patient was analized showing that it was homocygote for one allele (genotype: CYP2C9 *3/*3). Application of pharmacogenetic in clinical management and the prevention of secondary effects are discussed.

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