Iganidipine

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Iganidipine is a calcium channel blocker of the dihydropyridine class, primarily used in the management of hypertension and angina pectoris. It functions by inhibiting the influx of calcium ions through L-type calcium channels, which are predominantly found in the vascular smooth muscle and cardiac muscle. This action results in the relaxation of vascular smooth muscle, leading to vasodilation and a subsequent decrease in blood pressure.

Pharmacology

Iganidipine selectively targets the L-type calcium channels, which are responsible for the contraction of cardiac and smooth muscle. By blocking these channels, iganidipine reduces the contractility of the heart and dilates the arteries, thereby decreasing the workload on the heart and lowering blood pressure. This makes it effective in treating conditions such as hypertension and angina.

Mechanism of Action

Iganidipine binds to the alpha-1 subunit of the L-type calcium channels, inhibiting the transmembrane influx of calcium ions into cardiac and vascular smooth muscle cells. This inhibition leads to a decrease in intracellular calcium, which is necessary for muscle contraction. As a result, there is a reduction in peripheral vascular resistance and myocardial oxygen demand.

Pharmacokinetics

Iganidipine is well absorbed from the gastrointestinal tract, but it undergoes significant first-pass metabolism in the liver, resulting in a bioavailability of approximately 20-30%. It is highly protein-bound and is metabolized primarily by the liver enzyme CYP3A4. The metabolites are excreted mainly in the urine.

Clinical Use

Iganidipine is indicated for the treatment of hypertension and chronic stable angina. It may be used alone or in combination with other antihypertensive agents. The typical starting dose is 5 mg once daily, which may be increased based on patient response and tolerance.

Adverse Effects

Common side effects of iganidipine include headache, dizziness, flushing, and peripheral edema. These effects are generally mild and tend to diminish with continued use. Rarely, it may cause more serious side effects such as hypotension, bradycardia, or heart failure.

Contraindications

Iganidipine is contraindicated in patients with known hypersensitivity to dihydropyridines, severe hypotension, or cardiogenic shock. Caution is advised in patients with impaired hepatic function or severe aortic stenosis.

Drug Interactions

Iganidipine may interact with other medications that affect blood pressure, such as beta-blockers, ACE inhibitors, and other calcium channel blockers. It may also interact with drugs that are metabolized by CYP3A4, such as certain antifungals and antibiotics.

Also see

• Calcium channel blocker
• Hypertension
• Angina pectoris
• Dihydropyridine