Valsartan blocks the receptors that angiotensin II acts on and so prevents its actions. The main result of this is that the peripheral blood vessels are allowed to widen, which means that there is more space and less resistance in these blood vessels. This helps lower blood pressure. Amlodipine works by slowing the movement of calcium through the muscle cells that are found in the walls of blood vessels and heart. It does this by blocking ‘calcium channels’ in these muscle cells. Calcium is needed by muscle cells in order for them to contract, so by depriving them of calcium, amlodipine causes the muscle cells to relax. Amlodipine acts specifically on the muscle cells in the walls of arteries, causing them to relax. This allows the arteries in the body to widen.