Calcium channel blockers for hypertension: old, but still useful

Abstract

Calcium channel blockers (CCBs) constitute a heterogeneous class of drugs that can be divided into dihydropyridines (DHPs) and non-DHPs. DHP-CCBs are subcategorized into four generations based on the duration of activity and pharmacokinetics, while non-DHP-CCBs are subcategorized into phenylethylamine and benzodiazepine derivatives. DHP-CCBs are vascular-selective and function as potent vasodilators, whereas non-DHP-CCBs are cardiac-selective and are useful for treating tachyarrhythmia, but reduce cardiac contractility and heart rate. Traditional DHP-CCBs (nifedipine) mainly block L-type calcium channels, whereas novel CCBs block N-type (amlodipine) and/or T-type channels (efonidipine) in addition to L-type channels, leading to organ-protective effects. DHP-CCBs have a potent blood pressure–lowering effect and suppress atherosclerosis and coronary vasospasm. Diltiazem, a non-DHP-CCB, is highly effective for vasospasm control. CCBs reduce left ventricular hypertrophy and arterial stiffness. Amlodipine, a DHP-CCB, reduces blood pressure variability. L/N- and L/T-type CCBs combined with renin-angiotensin system blockers reduce proteinuria and improve kidney function compared with L-type CCBs. According to large-scale trials, DHP-CCBs reduce cardiovascular events in patients with isolated systolic hypertension, as well as in elderly and high-risk patients. Accordingly, CCBs are indicated for hypertension in elderly patients, isolated systolic hypertension, angina pectoris, and coronary vasospasm. Non-DHP-CCBs are contraindicated in high-grade heart block, bradycardia (<60 beats per minute [bpm]), and heart failure with reduced ejection fraction (HFrEF). DHP-CCBs should be used with caution in patients with tachyarrhythmia, HFrEF, and severe leg edema, and non-DHP-CCBs should be used carefully in those with constipation. Each CCB has distinct pharmacokinetics and side effects, underscoring the need for meticulous consideration in clinical practice.