An Investigation of CYP2D6 Genotype and Response to Metoprolol CR/XL During Dose Titration in Patients With Heart Failure: A MERIT-HF Substudy
- Batty, J. A.
- Hall, A. S.
- White, H. L.
- Wikstrand, J.
- de Boer, R. A.
- van Veldhuisen, D. J.
- van der Harst, P.
- Waagstein, F.
- Hjalmarson, A.
- Kjekshus, J.
- Balmforth, A. J.
DOIAbstract
To explore the pharmacogenetic effects of the cytochrome P450 (CYP) 2D6 genotype in patients with systolic heart failure treated using controlled/extended-release (CR/XL) metoprolol, this study assessed the CYP2D6 locus for the nonfunctional * 4 allele (1846G> A; rs3892097) in the Metoprolol CR/XL Randomised Intervention Trial in Congestive Heart Failure (MERIT-HF; n = 605). Participants were characterized as extensive, intermediate, or poor metabolizers (EMs, IMs, or PMs, respectively), based on the presence of the CYP2D6* 4 allele (EM: * 1* 1, 60.4%; IM: * 1* 4, 35.8%; and PM: * 4* 4, 3.8%). Plasma metoprolol concentrations were 2.1-/4.6-fold greater in the IM/PM groups as compared with the EM group (P <0.0001). Metoprolol induced signifi...