Cardizem (diltiazem hydrochloride) is a prescription calcium channel blocker medication specifically formulated for the management of hypertension, chronic stable angina, and atrial arrhythmias. Developed through advanced pharmaceutical research, it represents a cornerstone therapy in cardiovascular medicine. Its mechanism of action targets vascular smooth muscle and cardiac conduction tissue, offering clinicians a reliable tool for improving hemodynamic parameters. This comprehensive profile details its appropriate use under medical supervision.

Features

• Active pharmaceutical ingredient: Diltiazem hydrochloride
• Available in multiple formulations: immediate-release tablets, extended-release capsules, and intravenous injection
• Standardized manufacturing ensuring consistent bioavailability
• FDA-approved for specific cardiovascular indications
• Chemical structure: benzothiazepine derivative
• Half-life varies by formulation (3–7 hours for immediate-release; longer for extended-release)

Benefits

• Effectively lowers elevated blood pressure, reducing long-term cardiovascular risk
• Decreases myocardial oxygen demand, alleviating angina symptoms
• Controls ventricular rate in atrial fibrillation and flutter
• Provides 24-hour coverage with extended-release formulations
• Demonstrates favorable safety profile in appropriate patient populations
• May be used as monotherapy or in combination with other antihypertensives

Common use

Cardizem is primarily indicated for the treatment of hypertension (high blood pressure), either as monotherapy or in combination with other antihypertensive agents. It is also approved for management of chronic stable angina and for control of ventricular rate in patients with atrial fibrillation or atrial flutter. The medication works by inhibiting calcium ion influx during cardiac and vascular smooth muscle depolarization, resulting in reduced peripheral vascular resistance and decreased myocardial contractility. Clinical studies demonstrate its efficacy across diverse patient populations when dosed appropriately.

Dosage and direction

Dosage must be individualized based on patient response and tolerance. For hypertension: Initial dose typically ranges from 180-240 mg once daily (extended-release), titrated upward at 2-week intervals. Maximum dose: 540 mg daily. For angina: Initial dose 120-180 mg once daily, maximum 480 mg daily. For atrial arrhythmias: Intravenous administration requires careful titration under continuous monitoring. Tablets should be swallowed whole, not crushed or chewed. Administration with food may minimize gastrointestinal discomfort. Regular blood pressure monitoring is essential during dosage adjustments.

Precautions

Patients should be monitored for development of hypotension, particularly during initial titration. Hepatic and renal function should be assessed periodically as diltiazem is metabolized by the liver and excreted through kidneys. Use with caution in patients with impaired ventricular function or conduction abnormalities. Gradual withdrawal is recommended to avoid rebound angina. Patients should be advised about potential dizziness, especially when rising quickly from sitting or lying positions. Regular ophthalmological examinations are advised during long-term therapy.

Contraindications

Cardizem is contraindicated in patients with sick sinus syndrome or second- or third-degree AV block (except with functioning ventricular pacemaker), hypotension (systolic pressure <90 mmHg), acute myocardial infarction with pulmonary congestion, hypersensitivity to diltiazem, and patients with ventricular tachycardia. The intravenous formulation is additionally contraindicated in patients with atrial fibrillation/flutter complicating Wolff-Parkinson-White syndrome. Concomitant use with strong CYP3A4 inhibitors requires careful risk-benefit assessment.

Possible side effect

Common adverse reactions include headache (experienced by approximately 12% of patients), dizziness (10%), edema (8%), asthenia (7%), and first-degree AV block (5%). Less frequent side effects include flushing, nausea, rash, and bradycardia. Serious but rare adverse events include symptomatic hypotension, heart failure exacerbation, hepatotoxicity, and severe dermatological reactions. Laboratory abnormalities may include transient elevations in liver enzymes. Most side effects are dose-dependent and often diminish with continued therapy or dosage adjustment.

Drug interaction

Diltiazem is a moderate CYP3A4 inhibitor and substrate, resulting in numerous potential interactions. Concomitant use with beta-blockers may potentiate cardiac conduction effects. Increased digoxin levels (approximately 20-50%) require monitoring. Enhanced effects occur with other antihypertensives. Statins metabolized by CYP3A4 (atorvastatin, simvastatin) may require dosage reduction. Cyclosporine levels may increase significantly. Carbamazepine, phenytoin, and rifampin may decrease diltiazem concentrations. Anesthetic agents may potentiate cardiovascular effects. Comprehensive medication review is essential before initiation.

Missed dose

If a dose is missed, it should be taken as soon as remembered unless it is nearly time for the next scheduled dose. In that case, the missed dose should be skipped and the regular dosing schedule resumed. Patients should never take a double dose to make up for a missed one. For extended-release formulations, maintaining consistent dosing intervals is particularly important for stable therapeutic effects. Patients should be educated about the importance of adherence and provided with strategies to minimize missed doses.

Overdose

Overdose may manifest as excessive hypotension, bradycardia, heart failure, or conduction abnormalities. Symptoms include dizziness, syncope, confusion, and dyspnea. Management includes cardiovascular monitoring, elevation of lower extremities, and administration of intravenous fluids. Calcium gluconate (10%) may be administered intravenously. Vasopressors such as dopamine or norepinephrine may be required for refractory hypotension. Atropine may be used for bradycardia. Cardiac pacing may be necessary for conduction disturbances. Hemodialysis is not effective due to high protein binding.

Storage

Store at controlled room temperature (20-25°C or 68-77°F), protecting from moisture and light. Keep in the original container with the lid tightly closed. Do not transfer to other containers. Keep out of reach of children and pets. Do not use if capsules appear damaged or tablets show signs of discoloration. Proper disposal of unused medication through take-back programs is recommended to prevent accidental ingestion or environmental contamination.

Disclaimer

This information is provided for educational purposes only and does not constitute medical advice. Cardizem is a prescription medication that should be used only under the supervision of a qualified healthcare professional. Individual response to therapy may vary. Patients should consult their physician for diagnosis and treatment recommendations. Never initiate, adjust, or discontinue medication without professional medical guidance. Full prescribing information should be reviewed before use.

Reviews

Clinical trials demonstrate Cardizem’s efficacy with 70-80% of hypertensive patients achieving blood pressure control. Angina patients typically experience 40-60% reduction in attack frequency. Cardiologists frequently note its favorable side effect profile compared to other antihypertensives. Many patients report improved quality of life due to reduced symptoms and once-daily dosing convenience. However, some reviews note the need for careful titration in elderly patients and those with comorbidities. Overall professional assessment considers it a valuable therapeutic option within its indicated uses.