amlodipine
Norvasc (amlodipine) is a long-acting calcium channel blocker. By relaxing the muscle in blood vessel walls and easing the heart's workload, it lowers blood pressure and relieves angina. It is used alone or with other medicines for hypertension and coronary artery disease.
This page is based on FDA prescribing information and Health Canada product information for amlodipine; the mechanism is explained in plain language, and analogies are used only where they stay accurate.
How it works
Explains what the medicine does in the body, not dosing, side effects, or safety.
An analogy
Tight arteries are like garden hoses squeezed by a hand, forcing the pump upstream to strain. Amlodipine relaxes that grip by blocking the calcium signals that keep the hose wall tense, so the channel widens, pressure falls, and the heart does not have to push as hard.
In simple terms
Amlodipine belongs to a class of medicines called calcium channel blockers. It stops calcium from entering the muscle cells that line arteries, which makes those vessels relax and widen. Wider vessels mean lower blood pressure, and the heart can pump against less resistance. In angina, the relaxed coronary arteries also deliver more blood to the heart muscle.
In depth
Amlodipine is a dihydropyridine calcium antagonist that inhibits the transmembrane influx of calcium ions into vascular smooth muscle and myocardium during depolarisation, with selectivity for vascular smooth muscle at therapeutic doses. Reduced peripheral vascular resistance lowers blood pressure without clinically significant reflex tachycardia; in angina it decreases afterload and myocardial oxygen demand and dilates coronary arteries and arterioles. Its slow absorption and long half-life permit once-daily dosing.
See it in motion
A schematic animation of the mechanism — simplified for clarity, not drawn to scale.
How calcium-channel blockers work
- L-type calcium channels let calcium into heart and blood-vessel muscle cells.
- The drug blocks these channels, stopping calcium from entering the muscle cells.
- With less calcium inside, muscle contraction eases and vessels widen.
- Blood pressure falls and the heart works against less resistance.
Target: L-type voltage-gated calcium channels
Channels on vascular smooth muscle and cardiac cells that let calcium in to trigger contraction; their activity sets how tightly arteries are clamped and how hard the heart works.
Approved uses
Approved uses differ by country and change over time. Always follow your local prescribing information.
Approved uses in United States
FDA- Treatment of hypertension, to lower blood pressure, alone or in combination with other antihypertensive agents
- Chronic stable angina, alone or in combination with other antianginal agents
- Vasospastic (Prinzmetal's or variant) angina, alone or in combination with other antianginal agents
- Angiographically documented coronary artery disease in patients without heart failure or an ejection fraction below 40 percent, to reduce hospitalization for angina and revascularization procedures
Official sources
The statements on this page trace back to these records.
- U.S. Food and Drug Administration: amlodipine prescribing information
U.S. Food and Drug Administration
This page explains how the medicine works — it isn’t the patient leaflet. For anything that applies to you, read the leaflet that came with your medicine or ask your pharmacist.
MedUnfold provides educational content and is not medical advice. Always follow your local prescribing information and healthcare professional.