What is the primary effect of calcium channel blockers?

Calcium channel blockers primarily function by relaxing blood vessels and reducing the workload of the heart. They achieve this by inhibiting the influx of calcium ions through voltage-gated calcium channels in smooth muscle cells and the heart. By blocking these channels, calcium channel blockers cause vasodilation, which leads to a decrease in peripheral vascular resistance. This reduction in vascular resistance allows the heart to pump blood more easily, ultimately lowering blood pressure and decreasing the workload on the heart.

Additionally, the decreased calcium availability results in a decreased force of contraction in cardiac muscle, leading to reduced myocardial oxygen demand. These mechanisms make calcium channel blockers effective in treating conditions such as hypertension, angina, and certain arrhythmias. Their ability to relax blood vessels directly also aids in improving blood flow, further contributing to their therapeutic effectiveness.