In terms of effects on blood pressure, what is the primary mechanism of Diltiazem?

Diltiazem primarily works as a calcium channel blocker, which plays a significant role in lowering blood pressure through its effects on the vascular smooth muscle. The key mechanism is the reduction of peripheral vascular resistance. When Diltiazem is administered, it causes relaxation of vascular smooth muscle, leading to vasodilation of the arteries. This dilation allows blood to flow more easily through the vessels, effectively lowering the overall peripheral vascular resistance and, consequently, reducing blood pressure.

This action contrasts with increasing sodium retention, which would lead to higher blood pressure, and increased myocardial oxygen demand or contractility, which typically would result in greater workload on the heart. Diltiazem instead decreases contractility in the heart, but its most prominent effect relevant to blood pressure management is the vasodilation that leads to decreased peripheral resistance.