Drug Card: Diltiazem

Medication Name: Diltiazem

• Generic Name: Diltiazem

• Trade Name(s): Cardizem, Dilacor XR

Drug Classification: Calcium channel blocker

Description:
Diltiazem is used to treat hypertension and atrial fibrillation. It helps reduce heart rate and myocardial oxygen demand.

Mechanism of Action:
Diltiazem inhibits the influx of calcium ions into cardiac and smooth muscle cells, leading to decreased myocardial contractility and relaxation of vascular smooth muscle.

Pharmacokinetics:

• Absorption: Well absorbed; oral bioavailability is about 40%.

• Distribution: Widely distributed in tissues; crosses the blood-brain barrier.

• Metabolism: Primarily metabolized by the liver.

• Excretion: Excreted in urine; half-life is about 3-5 hours.

Indications/Field Use:

• Atrial fibrillation/flutter

• Hypertension

Contraindications:

• Severe hypotension

• 2nd or 3rd degree AV block (unless a pacemaker is present)

• Hypersensitivity to diltiazem

Side Effects/Adverse Reactions:

• Bradycardia

• Hypotension

• Dizziness

• Peripheral edema

Dose:

• Atrial Fibrillation: 15-20 mg IV over 2 minutes; may repeat every 15 minutes up to 30 mg.

Precautions:

• Monitor heart rate and blood pressure closely.

• Use caution in patients with heart failure.

Drug-Drug Interactions:

• May increase levels of other antihypertensives.

• Caution with other calcium channel blockers.