Amlodipine maleate

Amlodipine maleate is a calcium channel blocker used primarily in the treatment of hypertension and angina pectoris. It is a long-acting dihydropyridine-type calcium channel antagonist that works by relaxing the smooth muscle in the arterial walls, leading to a decrease in peripheral vascular resistance and a subsequent reduction in blood pressure.

Pharmacology

Amlodipine maleate is a dihydropyridine calcium channel blocker that inhibits the influx of calcium ions into vascular smooth muscle and cardiac muscle. This action results in a decrease in peripheral vascular resistance and a reduction in blood pressure. Amlodipine has a high affinity for vascular smooth muscle, which makes it particularly effective in treating hypertension.

Mechanism of Action

Amlodipine maleate works by blocking the L-type calcium channels in the smooth muscle cells of the vasculature. This blockade prevents calcium from entering the cells, which is necessary for muscle contraction. As a result, the smooth muscle relaxes, leading to vasodilation and a decrease in blood pressure. The reduction in afterload also decreases the oxygen demand of the heart, making it useful in treating angina.

Pharmacokinetics

Amlodipine is well absorbed after oral administration, with a bioavailability of 64–90%. It is extensively metabolized in the liver by the cytochrome P450 enzyme CYP3A4. The drug has a long elimination half-life of 30–50 hours, allowing for once-daily dosing. Approximately 60% of the drug is excreted in the urine, with the remainder eliminated in feces.

Clinical Uses

Amlodipine maleate is indicated for the treatment of hypertension and coronary artery disease, including chronic stable angina and vasospastic angina. It can be used as monotherapy or in combination with other antihypertensive agents.

Hypertension

In patients with hypertension, amlodipine maleate is effective in lowering blood pressure and reducing the risk of cardiovascular events. It is often used as a first-line agent due to its efficacy and favorable side effect profile.

Angina

Amlodipine is effective in the management of angina pectoris. It reduces the frequency and severity of angina attacks by decreasing myocardial oxygen demand and increasing oxygen delivery to the heart muscle.

Adverse Effects

Common side effects of amlodipine maleate include peripheral edema, dizziness, palpitations, and fatigue. These effects are generally mild and tend to resolve with continued use. Serious adverse effects are rare but may include hypotension, worsening of angina, and allergic reactions.

Contraindications

Amlodipine maleate is contraindicated in patients with known hypersensitivity to amlodipine or any of its components. Caution is advised in patients with severe aortic stenosis, as the reduction in afterload may worsen symptoms.

Drug Interactions

Amlodipine may interact with other medications metabolized by CYP3A4, such as simvastatin and cyclosporine. It may also potentiate the effects of other antihypertensive agents, leading to an increased risk of hypotension.

Dosage and Administration

Amlodipine maleate is typically administered orally once daily. The usual starting dose for adults is 5 mg, which may be increased to a maximum of 10 mg depending on the patient's response and tolerance.

See Also

• Calcium channel blocker
• Hypertension
• Angina pectoris

External Links

• [FDA Label for Amlodipine Maleate]
• [MedlinePlus Drug Information]