Iprotiazem

Iprotiazem

Iprotiazem is a pharmaceutical compound that belongs to the class of calcium channel blockers. It is primarily used in the management of cardiovascular conditions such as hypertension and angina pectoris. Iprotiazem functions by inhibiting the influx of calcium ions through L-type calcium channels, which are predominantly found in the cardiac and smooth muscle tissues. This action results in vasodilation and a reduction in cardiac workload.

Pharmacology

Iprotiazem is a calcium channel blocker, specifically targeting the L-type calcium channels. By blocking these channels, iprotiazem decreases intracellular calcium concentrations, leading to relaxation of vascular smooth muscle and subsequent vasodilation. This mechanism helps in reducing systemic vascular resistance and lowering blood pressure.

Mechanism of Action

The primary mechanism of action of iprotiazem involves the inhibition of calcium ion entry into cardiac and smooth muscle cells. This is achieved by binding to the alpha-1 subunit of the L-type calcium channels, which are responsible for the rapid influx of calcium ions during depolarization. The blockade of these channels results in decreased myocardial contractility and dilation of the coronary and peripheral arteries.

Pharmacokinetics

Iprotiazem is well absorbed from the gastrointestinal tract, with peak plasma concentrations occurring approximately 2 to 4 hours after oral administration. It undergoes extensive first-pass metabolism in the liver, resulting in a bioavailability of about 40-60%. The drug is highly protein-bound and is metabolized primarily by the cytochrome P450 enzyme system, particularly CYP3A4. The elimination half-life of iprotiazem is approximately 6 to 8 hours, and it is excreted mainly in the urine as metabolites.

Clinical Uses

Iprotiazem is indicated for the treatment of hypertension and angina pectoris. It may be used alone or in combination with other antihypertensive agents. The drug is effective in reducing blood pressure and improving exercise tolerance in patients with chronic stable angina.

Dosage and Administration

The typical starting dose of iprotiazem for adults is 60 mg taken orally twice daily. The dose may be adjusted based on the patient's response and tolerance, with a maximum recommended dose of 120 mg twice daily. It is important to monitor blood pressure and heart rate regularly during treatment.

Adverse Effects

Common adverse effects of iprotiazem include headache, dizziness, flushing, and peripheral edema. Less common but more serious side effects may include bradycardia, hypotension, and heart block. Patients should be monitored for signs of excessive vasodilation and cardiac depression.

Contraindications

Iprotiazem is contraindicated in patients with severe hypotension, cardiogenic shock, and advanced heart block (unless a pacemaker is present). It should be used with caution in patients with impaired hepatic function and in those taking other medications that affect cardiac conduction.

Drug Interactions

Iprotiazem may interact with other medications that affect cardiac conduction, such as beta-blockers and digoxin. It can also interact with drugs metabolized by the CYP3A4 enzyme, such as certain statins and antifungal agents. Patients should be advised to inform their healthcare provider of all medications they are taking.

Also see

• Calcium channel blocker
• Hypertension
• Angina pectoris
• L-type calcium channel