Cardizem (diltiazem hydrochloride) is a prescription calcium channel blocker medication specifically formulated for the management of chronic cardiovascular conditions. It functions by relaxing blood vessels and reducing the heart’s workload, thereby improving blood flow and oxygen supply to the heart muscle. This medication is a cornerstone in therapeutic regimens for hypertension and chronic stable angina, offering a well-established efficacy and safety profile backed by extensive clinical use. Proper diagnosis and ongoing medical supervision are imperative for its safe and effective application.

Features

• Active Pharmaceutical Ingredient: Diltiazem hydrochloride.
• Available in multiple formulations: immediate-release tablets, extended-release capsules (Cardizem CD, Cardizem LA), and injectable solutions for hospital use.
• Mechanism of Action: Inhibits the influx of calcium ions during cardiac and vascular smooth muscle depolarization.
• Standardized dosing ensures consistent pharmacological effect.
• Manufactured under strict cGMP (current Good Manufacturing Practices) regulations for quality assurance.

Benefits

• Effectively lowers elevated blood pressure, reducing long-term risk of stroke, myocardial infarction, and kidney damage.
• Decreases the frequency and severity of angina pectoris episodes, improving exercise tolerance and quality of life.
• Helps to control heart rate in certain arrhythmias, such as atrial fibrillation or flutter.
• Offers a favorable side effect profile for many patients compared to other antihypertensive classes.
• Extended-release formulations provide 24-hour coverage with once-daily dosing, enhancing adherence.
• Works by directly affecting vascular tone and cardiac conduction, offering a targeted therapeutic approach.

Common use

Cardizem is primarily indicated for the treatment of hypertension (high blood pressure). It is also approved for the management of chronic stable angina and, for the injectable form, for the temporary control of rapid heart rate in atrial fibrillation or flutter. Its use is determined by a physician following a comprehensive cardiovascular assessment.

Dosage and direction

Dosage is highly individualized based on the patient’s condition, response to therapy, and the specific formulation prescribed. It must be precisely followed as directed by the physician.

• Hypertension/Angina (Oral): Initial doses typically range from 120 mg to 240 mg once daily for extended-release capsules (e.g., Cardizem CD, LA), or 30 mg four times daily for immediate-release tablets. Dosage may be adjusted at intervals of 1 to 2 weeks based on therapeutic response.
• Administration: Extended-release capsules (CD, LA) must be swallowed whole and must not be crushed, chewed, or divided. They may be taken with or without food but consistency is key. The tablet formulation is taken with food.
• Atrial Fibrillation/Flutter (Injectable): Administered via intravenous infusion under continuous ECG and blood pressure monitoring in a clinical setting. A bolus dose is followed by a continuous infusion, with dosage titrated to patient response.
• Never adjust the dose or frequency without consulting your healthcare provider.

Precautions

• Regular monitoring of blood pressure and heart rate is essential during therapy.
• Use with caution in patients with impaired liver or kidney function, as dosage adjustments will likely be necessary.
• May cause dizziness or lightheadedness, especially at the initiation of therapy. Patients should avoid driving or operating machinery until they know how the drug affects them.
• Abrupt discontinuation of therapy may exacerbate angina; dosage should be tapered under medical supervision.
• Inform all healthcare providers, including dentists, that you are taking Cardizem before any surgery or procedure.

Contraindications

Cardizem is contraindicated in patients with:

• Known hypersensitivity to diltiazem or any component of the formulation.
• Sick sinus syndrome or second- or third-degree AV block, except in the presence of a functioning ventricular pacemaker.
• Severe hypotension (systolic pressure < 90 mm Hg).
• Acute myocardial infarction and pulmonary congestion documented by x-ray on admission.
• IV administration with ventricular tachycardia.

Possible side effect

Like all medications, Cardizem can cause side effects, though not everyone experiences them. Common side effects are often dose-related and may diminish over time.

• Very Common (>10%): Headache, dizziness, edema (swelling of the ankles and feet), asthenia (weakness).
• Common (1-10%): Nausea, flushing, rash, bradycardia (slow heart rate), first-degree AV block.
• Uncommon (0.1-1%): Constipation, dyspepsia, hypotension, palpitations.
• Rare (<0.1%): Elevated liver enzymes, gingival hyperplasia, exfoliative dermatitis.
• Report any severe or persistent side effects to your doctor immediately.

Drug interaction

Cardizem is metabolized by the CYP450 3A4 enzyme system and has the potential for significant interactions.

• Contraindicated: Concomitant use with strong CYP3A4 inhibitors like ketoconazole, itraconazole, or clarithromycin can significantly increase diltiazem levels.
• Use with Extreme Caution:
  • Beta-blockers: May potentiate bradycardia and AV conduction disturbances.
  • Digoxin: Cardizem can increase serum digoxin levels; monitoring is required.
  • Statins (Simvastatin, Lovastatin): Increased risk of myopathy/rhabdomyolysis.
  • Cyclosporine, Carbamazepine, Buspirone: Cardizem can increase their plasma concentrations.
  • Anesthetics: Potentiates the effect of anesthetics; caution during surgery.
• Always provide your doctor and pharmacist with a complete list of all medications you are taking, including prescription, over-the-counter, and herbal products.

Missed dose

• If you miss a dose of the extended-release formulation, take it as soon as you remember on the same day.
• If it is almost time for your next dose, skip the missed dose and resume your regular dosing schedule.
• Do not take a double dose to make up for a missed one.
• For the immediate-release tablet taken multiple times a day, take the missed dose if it is within the appropriate interval before the next dose; otherwise, skip it.
• Consult your pharmacist or physician for specific guidance based on your regimen.

Overdose

Overdose can lead to severe hypotension, bradycardia, heart failure, and cardiac arrest. Symptoms may include dizziness, slurred speech, confusion, and shortness of breath.

• In case of suspected overdose, seek immediate emergency medical attention or call a poison control center.
• Treatment is supportive and may include activated charcoal (if ingestion was recent), IV fluids, vasopressors, atropine for bradycardia, and cardiac pacing. Inotropic agents may be required for heart failure.

Storage

• Store at room temperature between 20°C to 25°C (68°F to 77°F), in a tight, light-resistant container.
• Keep away from excess moisture, light, and heat.
• Keep all medications out of the reach of children and pets.
• Do not flush medications down the toilet or pour them into a drain. Dispose of unused medication through a official medicine take-back program.

Disclaimer

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or medication. Never disregard professional medical advice or delay in seeking it because of something you have read here. The information provided is not exhaustive and may not cover all possible uses, directions, precautions, interactions, or adverse effects.

Reviews

• “As a cardiologist with over 20 years of experience, Cardizem remains a reliable and effective first-line option for many of my hypertensive patients. Its predictable pharmacokinetics, especially with the LA formulation, make dose titration straightforward.” – Dr. A. Sharma, MD
• “Clinical trial data consistently supports its role in reducing anginal frequency. It’s a workhorse in our anti-anginal arsenal.” – Clinical Study Review, American Journal of Cardiology
• “Patient adherence is significantly improved with the once-daily dosing of the extended-release capsules compared to older multi-dose regimens.” – Review of Patient Outcomes Data
• “While generally well-tolerated, clinicians must remain vigilant for interactions with other commonly prescribed medications metabolized by the CYP3A4 pathway.” – Pharmacotherapy Advisory