Last reviewed 2026-04-20 · How we verify

Norvasc (Amlodipine Besylate)

Amlodipine inhibits calcium ion influx into vascular smooth muscle and cardiac muscle cells.

Amlodipine besylate is a dihydropyridine calcium channel antagonist indicated for hypertension and coronary artery disease including chronic stable angina, vasospastic angina, and angiographically documented coronary artery disease. The drug selectively inhibits calcium ion influx into vascular smooth muscle with greater potency than on cardiac muscle, resulting in peripheral vasodilation and blood pressure reduction. Key drug interactions include CYP3A inhibitors and inducers affecting amlodipine exposure, and amlodipine's effects on simvastatin, cyclosporine, and tacrolimus requiring dose adjustments or monitoring. Amlodipine is contraindicated only in patients with known sensitivity to the drug.

At a glance

Mechanism of action

Amlodipine is a dihydropyridine calcium antagonist that inhibits the transmembrane influx of calcium ions into vascular smooth muscle and cardiac muscle. Experimental data suggest that amlodipine binds to both dihydropyridine and nondihydropyridine binding sites. The contractile processes of cardiac muscle and vascular smooth muscle are dependent upon the movement of 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. Within the physiologic pH range, amlodipine is an ionized compound (pKa=8.6), and its kinetic interaction with the calcium channel receptor is characterized by a gradual rate of association and dissociation with the receptor binding site, resulting in a gradual onset of effect. Amlodipine is a peripheral arterial vasodilator that acts directly on vascular smooth muscle to cause a reduction in peripheral vascular resistance and reduction in blood pressure. In exertional angina, amlodipine reduces total peripheral resistance and rate pressure product, thus reducing myocardial oxygen demand. In vasospastic angina, amlodipine blocks constriction and restores blood flow in coronary arteries and arterioles.

Approved indications

• Hypertension
• Chronic Stable Angina
• Vasospastic Angina (Prinzmetal's or Variant Angina)
• Angiographically Documented Coronary Artery Disease (in patients without heart failure or ejection fraction <40%)

Common side effects

• Blood pressure decreased
• Hepatic function abnormal
• Blood urea increased
• Dizziness
• Gamma-glutamyltransferase increased
• Blood creatinine increased

Drug interactions

• CYP3A inhibitors (moderate and strong)
• CYP3A inducers
• Sildenafil
• Simvastatin
• Cyclosporine
• Tacrolimus

Patents

Primary sources

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