Lodi Mechanism of Action

Pharmacology: Pharmacodynamics and Pharmacokinetics: Amlodipine is a dihydropyridine calcium antagonist (calcium ion antagonist or slow-channel blocker) that inhibits the transmembrane influx of calcium ions into vascular smooth muscle and cardiac muscle. The contraction of the cardiac and vascular smooth muscle are dependent upon the movement or extracellular calcium ions into these cells through specific ion channels. Amlodipine inhibits calcium ion influx across cell membranes selectively, with a greater effect on vascular smooth muscle cells than on cardiac muscle cells. Amlodipine also exerts vasodilation to the peripheral arteries by direct action on the vascular smooth muscle causing a reduction in peripheral vascular resistance and blood pressure.
Amlodipine is well absorbed following oral administration with peak blood concentrations occurring after 6-12 hrs. The bioavailability is 60-65%. Amlodipine is reported to be about 97.5% bound to plasma proteins. It has a prolonged terminal elimination t_½ of 35-50 hrs and steady-state plasma concentrations are not achieved until after 7-8 days of administration. Amlodipine is extensively metabolized in the liver; metabolites are mostly excreted in the urine together with <10% of a dose as unchanged drug.