Pharmacology: Pharmacodynamics: Mechanism of Action: It is a combination of two drugs, a dihydropyridine calcium antagonist (calcium-channel blocker) amlodipine (antihypertensive/antianginal agent) and an HMG-CoA reductase inhibitor atorvastatin (cholesterol lowering agent). Amlodipine inhibits the transmembrane influx of calcium ions into vascular smooth muscle and cardiac muscle. Atorvastatin is a selective, competitive inhibitor of HMG-CoA reductase (statin), the rate-limiting enzyme that converts 3-hydroxy-3-methylglutaryl-coenzyme A to mevalonate, a precursor of sterols, including cholesterol.