CYP 2D6*4 polymorphism and interindividual response variation to metoprolol in stage 1 hypertensive patients: no association in a rural Indian population?

Authors: RAJAGOPAL AYYAPPADHAS, UNNIKRISHNAN DHANALEKSHMI, CHELLIAH JESTIN

Abstract: Background/aim: Genetic polymorphism of CYP2D6 shows diverse pharmacokinetic and pharmacodynamic variation. Therefore, the present work was designed to study the variation in therapeutic responses to metoprolol (MP) in stage 1 hypertensive patients and also aims to verify the association of CYP2D6*4 polymorphism and response variation in an Indian population for the first time. Materials and methods: Clinically, a total of 119 hypertensive patients and 116 healthy individuals as controls were included. Patients were treated with MP extended release 25 mg tablets once daily for 2 weeks. Reduction in systolic blood pressure, diastolic blood pressure, and pulse rate were recorded before and after the treatment. For genotyping, genotypes of 89 hypertensive patients and 71 healthy controls were investigated for CYP2D6*4 polymorphism. Results: Based on reduction in systolic blood pressure, 26% of the patients did not respond to the MP treatment. Of the patients that responded, 28% responded very slowly, 35% (19 males, 23 females) responded moderately, and 12% (8 males, 6 females) showed a good response to MP. For genotype analysis, we pooled 89 hypertensive patients and 71 controls. No association was found between CYP2D6*4 polymorphism and MP response. Conclusion: We found no relationship between MP response and CYP2D6*4 genotype in an Indian population in our study.

Keywords: Metoprolol, CYP2D6*4, polymorphism, hypertension

Full Text: PDF