Nifedipine works primarily by blocking calcium channels in vascular smooth muscle cells. These channels regulate the flow of calcium ions into the cells, which is crucial for muscle contraction. By blocking these channels, nifedipine inhibits the influx of calcium ions, leading to relaxation of the smooth muscle cells in the walls of arteries.
This relaxation results in dilation (widening) of the arteries, reducing peripheral vascular resistance and making it easier for the heart to pump blood against a lower resistance. As a consequence, nifedipine helps to lower blood pressure by decreasing the force needed for the heart to pump blood throughout the body.
In addition to its effects on blood vessels, nifedipine also has some actions on the heart itself. It can reduce the workload on the heart by decreasing the demand for oxygen, which can be beneficial in conditions like angina (chest pain) where there is inadequate blood flow to the heart muscle.
Nifedipine is classified as a dihydropyridine calcium channel blocker, which means it primarily affects calcium channels in vascular smooth muscle. This mechanism distinguishes it from other types of calcium channel blockers that may have different effects on the heart and blood vessels.
Overall, nifedipine's ability to relax arterial smooth muscle and reduce vascular resistance plays a central role in its therapeutic actions in treating conditions such as hypertension and angina. It is important for patients to take nifedipine as prescribed by their healthcare provider to achieve optimal control of their blood pressure or symptoms of angina.