Calcium Channel Blockers

Calcium channel blockers (CCBs) are a class of medications primarily used to treat cardiovascular conditions such as hypertension, angina, and certain arrhythmias. Their therapeutic effect is derived from their ability to inhibit the influx of calcium ions (Ca²⁺) into cardiac and smooth muscle cells via voltage-gated calcium channels. By blocking this calcium entry, CCBs reduce muscle contraction, leading to vasodilation, decreased heart rate, and reduced myocardial oxygen demand.

Calcium plays a critical role in muscle contraction, especially in the smooth muscles of blood vessels and the myocardium. By limiting calcium's entry into these cells, CCBs help relax vascular smooth muscle, which reduces peripheral resistance and lowers blood pressure. Additionally, in the heart, they can decrease the force of contraction and slow down the heart rate, making them valuable for treating conditions like angina and certain arrhythmias.