Maack et al. [70] recently reported on switching between β blockers (metoprolol and carvedilol) in 68 patients treated with either agent for 1 year who had improved in terms of LVEF and NYHA class.

Metoprolol is used for phenotyping of cytochrome P450 (CYP) 2D6, a CYP isoform considered not to be inducible by inducers of the CYP2C, CYP2B, and CYP3A families such as rifampicin. While assessing ...