The pharmacogenetics of β-adrenergic receptor antagonists in the treatment of hypertension and heart failure.

INTRODUCTION: β-Blockers have an important therapeutic role throughout the cardiovascular continuum. However, there is considerable variation in response to these drugs, which may be related to genetic influences on their pharmacokinetics and pharmacodynamic effects. AREAS COVERED: This review focuses on genetic variations in the drug metabolizing enzymes which influence the pharmacokinetics and potentially the pharmacodynamics of some β-blockers. It also reviews the polymorphisms in the adrenergic receptors (ARs) and their related pathways which are likely to influence the responses to β-blockers. EXPERT OPINION: The CYP2D6 genotypes influence the pharmacokinetics of some β-blockers but the effects on β-blocker responses have been inconsistent and there is currently no general role for CYP2D6 genotyping prior to choosing a particular β-blocker or dose. The common polymorphisms producing changes in the β(1)-ARs, and their signaling pathways, have been associated with clinical outcomes in several studies in hypertension and heart failure. Treatment with β-blockers, especially with higher doses, appears to have greater benefits in patients with the genetic forms of the β(1)-ARs which are more responsive to both agonists and antagonists. However, current data are not sufficiently consistent to support genotyping for these polymorphisms before selecting or initiating β-blocker treatment and further study results are needed to clarify the situation.