Pharmacology Proctored ATI Practice Exam

Calcium channel blockers primarily work by inhibiting the movement of calcium ions into the muscle cells of the heart and blood vessels. This action results in a decrease in the contractility of the heart muscle, meaning the heart's ability to contract forcefully is diminished. As a consequence, this reduction in contractility leads to a decrease in the overall workload of the heart, which can result in lower blood pressure. Additionally, because the vascular smooth muscle also relaxes due to reduced calcium influx, peripheral vascular resistance decreases, contributing further to blood pressure reduction.

The therapeutic effects of calcium channel blockers are particularly beneficial for conditions such as hypertension and certain types of angina, as they relax blood vessels and lower the heart's demand for oxygen. Therefore, the correct understanding of calcium channel blockers is that they lower both heart contractility and blood pressure, making them effective medications in managing various cardiovascular conditions.