Calcium channel blockers (CCBs), like amlodipine, reduce blood pressure primarily by reducing smooth muscle contraction in peripheral arterial vessel walls.1,2 CCBs block the transport of calcium ions through specific membrane channels which results in dilation of peripheral arterial blood vessels, some antiarrhythmic effects, and reduction of myocardial ischemia.
There are several classes of CCBs. Dihydropyridine (DHP) CCBs, like amlodipine, are based on the compound pyridine.3 They act selectively on peripheral blood vessels to counter the constriction effects of the sympathetic nervous system and renin-angiotensin system.
Amlodipine has a long half-life and longer duration of action than other DHP CCBs. It results in better control of blood pressure over 24 hours, better nighttime control of blood pressure, and lower variability of blood pressure over time, compared to other anti-hypertensive classes and compared to extended-release DHB CCBs.3–6 The longer-acting DHP CCBs also minimize the compensatory effects on heart rate and the renin-angiotensin system.7
Some studies have suggested that there are additional non-calcium-related cardiovascular benefits of CCBs.8–10 These include anti-oxidant effects and anti-atherosclerotic effects. Further randomized controlled studies need to be done before these potential benefits can be measured with respect to cardiovascular outcomes of morbidity and mortality.
References
- Cohn J. Calcium, vascular smooth muscle, and calcium entry blockers in hypertension. Ann Intern Med 1983; 98 (Part 2): 806-809.
- Victor RG LP. Systemic hypertesion: management. In: Zipes DP, Libby P, Bonow R, Mann DL TGBE, ed. Braunwald’s Heart Disease: A Textbook of Cardiovascular Medicine. 11th ed. Philadelphia,PA: Elsevier; 2019:928-259.
- Chaugai S, Arima H, Sherpa LY, Sepehry A. Effects of long and intermediate acting dihydropyridine calcium channel blockers in hypertension: a systematic review and meta-analysis of 18 prospective, actively controlled, randomized clinical trials. Hypertension 2017; 70 (Suppl 1).
- Hughes A. Calcium channel blockers. In: Bakris GL SM, ed. Hypertension: A Companion to Braunwald’s Heart Disease. 3rd ed. Philadelphia,PA; 2018:242-253.
- Leenen F. Clinical relevance of 24 h blood pressure control by 1,4-dihydropyridines. Am J Hypertens 1996; 9 (10 pt 2): 97S-104S.
- Wang JG, Yan P, Jeffers BW. Effects of amlodipine and other classes of antihypertensive drugs on long-term blood pressure variability: evidence from randomized controlled trials. J Am Soc Hypertens 2014; 8 (5): 340-349.
- Krakoff R. Diagnosis and treatment of hypertension. In: Fuster V, Harrington RA, Narula J EZ, ed. Hurst’s the Heart. 14th ed. New York, NY: McGraw Hill; 2017.
- Mason RP. Mechanisms of plaque stabilization for the dihydropyridine calcium channel blocker amlodipine: review of the evidence. Atherosclerosis 2002; 165 (2): 191-199.
- Mason RP, Marche P, Hintze TH. Novel vascular biology of third-generation L-type calcium channel antagonists: ancillary actions of amlodipine. Arterioscler Thromb Vasc Biol 2003; 23 (12): 2155-2163.
- Park CG. Is amlodipine more cardioprotective than other antihypertensive drug classes? Korean J Intern Med 2014; 29 (3): 301-304.
Amlodipine lowers blood pressure by blocking calcium from entering muscles in blood vessel walls. This relaxes and widens the vessels. It makes it easier for the heart to pump blood through the body. This is why amlodipine is called a calcium channel blocker. 
