Calan (verapamil hydrochloride) is a premium calcium channel blocker medication specifically engineered for the management of hypertension, chronic stable angina, and vasospastic angina. Developed through rigorous clinical research, Calan effectively modulates cardiovascular function by inhibiting calcium ion influx across cardiac and vascular smooth muscle cell membranes. This action results in reduced peripheral vascular resistance, decreased myocardial oxygen demand, and improved coronary blood flow—delivering comprehensive cardiovascular protection with well-established efficacy and safety profiles. Trusted by cardiologists worldwide, Calan represents a cornerstone therapy in modern cardiovascular pharmacotherapy with decades of clinical validation supporting its use in diverse patient populations.

Features

• Contains verapamil hydrochloride as the active pharmaceutical ingredient
• Available in immediate-release (80mg, 120mg) and extended-release formulations (120mg, 180mg, 240mg)
• Exhibits selective inhibition of L-type calcium channels
• Demonstrates high oral bioavailability (20-35%) with extensive first-pass metabolism
• Provides dose-dependent reduction in blood pressure and angina frequency
• Features predictable pharmacokinetics with linear dose-response relationship
• Manufactured under cGMP standards with consistent quality assurance
• Includes clearly marked tablet identification codes for dosage verification

Benefits

• Significantly reduces systolic and diastolic blood pressure through vasodilation
• Decreases angina pectoris episodes by improving myocardial oxygen supply-demand ratio
• Lowers cardiovascular event risk in hypertensive patients through sustained BP control
• Provides 24-hour therapeutic coverage with extended-release formulations
• Demonstrates favorable safety profile with extensive clinical experience
• Offers convenient once-daily dosing option for improved adherence

Common use

Calan is primarily prescribed for the management of essential hypertension, either as monotherapy or in combination with other antihypertensive agents. In cardiology practice, it is extensively used for the treatment of chronic stable angina pectoris when beta-blockers are contraindicated or ineffective. The medication also demonstrates efficacy in managing vasospastic (Prinzmetal’s) angina and certain supraventricular arrhythmias, particularly for controlling ventricular rate in atrial fibrillation and flutter. Off-label applications include migraine prophylaxis, hypertrophic cardiomyopathy management, and Raynaud’s phenomenon treatment, though these uses require careful medical supervision.

Dosage and direction

For hypertension management, initial dosing typically begins with 80mg three times daily for immediate-release formulations, with titration based on therapeutic response up to 360mg daily in divided doses. Extended-release formulations allow for once-daily administration starting at 180mg, with maximum recommended dosage of 480mg daily. Angina treatment follows similar dosing protocols, with regular assessment of therapeutic efficacy and side effect profile. Administration with food may enhance bioavailability while minimizing gastrointestinal discomfort. Dose adjustments are necessary for elderly patients, those with hepatic impairment, or individuals taking concomitant medications that affect verapamil metabolism. Regular blood pressure monitoring and clinical assessment are essential during dosage titration periods.

Precautions

Patients should undergo comprehensive cardiovascular assessment before initiating Calan therapy, including liver function tests and electrocardiogram evaluation. Caution is advised in patients with compromised cardiac function, as verapamil may exacerbate heart failure in susceptible individuals. Regular monitoring of blood pressure, heart rate, and clinical status is mandatory during treatment initiation and dosage adjustments. Patients should be advised about potential dizziness, especially during initial therapy or dosage increases. Grapefruit juice consumption should be avoided due to inhibition of CYP3A4 metabolism, potentially leading to increased verapamil concentrations. Abrupt discontinuation should be avoided due to potential rebound hypertension or angina exacerbation.

Contraindications

Calan is strictly contraindicated in patients with severe left ventricular dysfunction, sick sinus syndrome, or second- or third-degree AV block without functioning pacemaker. Additional contraindications include hypotension (systolic pressure <90 mmHg), cardiogenic shock, atrial flutter/fibrillation with accessory pathway syndromes, and known hypersensitivity to verapamil or any component of the formulation. Concurrent administration with ivabradine is contraindicated due to additive heart rate lowering effects. The medication should not be used in patients with severe hepatic impairment (Child-Pugh Class C) due to significantly reduced metabolism and potential toxicity.

Possible side effect

Common adverse reactions include constipation (7-25%), dizziness (3-10%), nausea (2-7%), hypotension (2-5%), and peripheral edema (2-5%). Less frequent side effects comprise headache, fatigue, flushing, and bradycardia. Serious but rare adverse events include heart failure exacerbation, AV block, hepatotoxicity, and gingival hyperplasia with prolonged use. Constipation may be managed with appropriate dietary measures or laxatives, while cardiovascular effects typically require dosage adjustment or discontinuation. Most side effects are dose-dependent and often diminish with continued therapy or appropriate dosage reduction.

Drug interaction

Calan demonstrates significant interaction potential due to CYP3A4 metabolism. Concomitant use with beta-blockers may produce additive negative chronotropic and inotropic effects. Concurrent administration with digoxin increases digoxin concentrations by 50-75%, requiring dosage reduction and monitoring. Statins metabolized by CYP3A4 (atorvastatin, simvastatin) may experience increased exposure. Calan potentiates effects of neuromuscular blocking agents and lithium while reducing efficacy of theophylline. Rifampin, phenytoin, and St. John’s wort decrease verapamil concentrations through CYP3A4 induction. Concomitant use with disopyramide or flecainide within 48 hours may produce excessive negative inotropy.

Missed dose

If a dose is missed, patients should take it as soon as remembered unless the next scheduled dose is within 4 hours for immediate-release formulations or 12 hours for extended-release preparations. Doubling doses to compensate for missed administration is strictly contraindicated due to risk of excessive hypotension or bradycardia. Patients should maintain regular dosing schedules and utilize pill organizers or reminder systems if adherence issues persist. Healthcare providers should be consulted if multiple doses are missed to determine appropriate management strategy.

Overdose

Verapamil overdose presents with profound hypotension, bradycardia, and potential cardiovascular collapse. Symptoms may include confusion, drowsiness, reduced consciousness, and metabolic acidosis. Management requires immediate medical attention with continuous hemodynamic monitoring. Treatment includes gastric lavage if presentation is early, activated charcoal administration, and aggressive cardiovascular support with intravenous fluids and vasopressors. Calcium gluconate (1g IV) may reverse cardiovascular effects, while atropine can address bradycardia. Temporary cardiac pacing may be necessary for severe conduction disturbances. Hemodialysis is ineffective due to high protein binding and extensive tissue distribution.

Storage

Store Calan tablets at controlled room temperature (20-25°C or 68-77°F) in original container with tight closure. Protect from excessive moisture, light, and heat. Keep out of reach of children and pets. Do not transfer tablets to alternative containers that may compromise stability. Discard any medication that appears discolored, shows signs of deterioration, or exceeds expiration date. Proper disposal through medication take-back programs is recommended to prevent environmental contamination or accidental ingestion.

Disclaimer

This information provides educational content about Calan but does not replace professional medical advice, diagnosis, or treatment. Always consult qualified healthcare providers regarding medical conditions or before starting any new treatment. Individual therapeutic responses may vary based on clinical status, comorbidities, and concomitant medications. Patients should not discontinue or modify dosage without medical supervision. The manufacturer and distributors are not liable for any adverse outcomes resulting from medication use without proper medical guidance.

Reviews

Clinical studies demonstrate Calan’s efficacy with 70-80% of hypertensive patients achieving target blood pressure control. Angina patients report 50-60% reduction in attack frequency and nitrate consumption. Long-term users appreciate the consistent therapeutic effect and convenient dosing options, though some note constipation as a manageable side effect. Cardiologists consistently rate Calan highly for its reliable hemodynamic effects and well-characterized safety profile, particularly praising its effectiveness in patients intolerant to beta-blockers. The medication maintains strong professional endorsement based on decades of clinical experience and ongoing positive outcomes in diverse patient populations.