12.03.5 β-Adrenoceptor Antagonists

For many years, it was considered that β-adrenoceptor antagonists would be detrimental in heart failure. Thus, b₁-adrenoceptor antagonists were used in the treatment of hypertension and angina, but contraindicated in the treatment of heart failure. Recently, b₁-adrenoceptor antagonists have been shown to be beneficial in heart failure. On the normal heart, b₁-adrenoceptor antagonists decrease cardiac output, and this would be detrimental in heart failure, and this was the reason for not considering b₁-adrenoceptor antagonists in heart failure. However, we now know that b₁-blockers have different effects in the failing than normal heart. In heart failure, the number of b₁-adrenoceptors is altered, and b₁-adrenoceptor antagonists have been shown to increase cardiac output. The b₁-adrenoceptors, such as metoprolol, have been shown to decrease mortality and morbidity in subjects with heart failure. b₁-adrenoceptor antagonists are now very commonly used in the treatment of heart failure.