Calan

Calan (verapamil hydrochloride) is a premium calcium channel blocker medication specifically engineered for the clinical management of hypertension, angina, and certain cardiac arrhythmias. Developed through rigorous pharmaceutical research, Calan operates by inhibiting calcium ion influx across cardiac and vascular smooth muscle cell membranes, resulting in reduced peripheral vascular resistance and decreased myocardial oxygen demand. This mechanism offers physicians a trusted therapeutic option for patients requiring precise blood pressure control and cardiovascular protection. Trusted in clinical practice for decades, Calan represents a cornerstone in cardiovascular pharmacotherapy, combining proven efficacy with a well-characterized safety profile.

Features

• Active ingredient: Verapamil hydrochloride
• Available in immediate-release and extended-release formulations
• Tablet strengths: 40 mg, 80 mg, 120 mg, 180 mg, 240 mg
• Chemical name: α-[3-[[2-(3,4-dimethoxyphenyl)ethyl]methylamino]propyl]-3,4-dimethoxy-α-(1-methylethyl)benzenecacetonitrile hydrochloride
• Molecular formula: C₂₇H₃₈N₂O₄·HCl
• White to off-white film-coated tablets with distinct scoring for accurate dosing
• Manufactured under cGMP (current Good Manufacturing Practice) standards
• Bioavailability: Approximately 20-35% due to first-pass metabolism
• Protein binding: 90%
• Half-life: 2.8-7.4 hours (immediate release); 4.5-12 hours (extended release)
• Primary metabolites: Norverapamil (active) and multiple inactive compounds
• Excretion: Approximately 70% renal, 16% fecal

Benefits

• Effectively lowers systolic and diastolic blood pressure through vasodilation
• Reduces frequency and severity of angina episodes by decreasing myocardial oxygen demand
• Controls certain supraventricular tachyarrhythmias by slowing AV nodal conduction
• Provides 24-hour blood pressure control with extended-release formulations
• May offer renal protective effects in hypertensive patients
• Demonstrates potential anti-atherosclerotic properties through vascular protection

Common use

Calan is predominantly prescribed for the management of essential hypertension, either as monotherapy or in combination with other antihypertensive agents. It is equally effective in treating chronic stable angina pectoris and vasospastic (Prinzmetal’s) angina. Cardiologists frequently utilize Calan for controlling supraventricular tachyarrhythmias, particularly for maintaining normal sinus rhythm following conversion of atrial fibrillation and flutter. Off-label uses include migraine prophylaxis, hypertrophic cardiomyopathy management, and Raynaud’s phenomenon treatment. The medication is typically incorporated into long-term treatment regimens for chronic cardiovascular conditions requiring sustained pharmacological intervention.

Dosage and direction

Dosage must be individualized based on therapeutic response and tolerability. For hypertension: Initial dose is 80 mg three times daily (immediate-release) or 180-240 mg once daily (extended-release). Maintenance doses may range from 240-480 mg daily in divided doses. For angina: Initial dose is 80-120 mg three times daily, with maximum recommended dose of 480 mg daily. For arrhythmias: Dosage ranges from 240-480 mg daily in divided doses. Extended-release tablets should be swallowed whole, not crushed or chewed, and may be taken with food to minimize gastrointestinal discomfort. Dosage adjustments are necessary for elderly patients and those with hepatic impairment. Regular blood pressure monitoring is essential during dosage titration.

Precautions

Patients should be cautioned about potential dizziness, especially during initial therapy or dosage adjustments. Regular monitoring of blood pressure, heart rate, and ECG is recommended. Hepatic function should be assessed periodically due to extensive liver metabolism. Use with caution in patients with impaired renal function, as dosage adjustments may be necessary. Abrupt discontinuation may cause rebound hypertension or angina exacerbation. Patients should avoid grapefruit juice consumption as it may increase verapamil concentrations. Caution is advised when operating machinery or performing hazardous activities until response to therapy is established.

Contraindications

Calan is contraindicated in patients with severe left ventricular dysfunction, hypotension (systolic pressure <90 mmHg), sick sinus syndrome or second- or third-degree AV block (except with functioning pacemaker), atrial flutter/fibrillation with accessory pathway, and known hypersensitivity to verapamil or any component of the formulation. Concurrent administration with ivabradine is contraindicated. The medication should not be used in patients with cardiogenic shock or acute myocardial infarction with pulmonary congestion.

Possible side effect

Common adverse reactions (≥5%) include constipation (7.3%), dizziness (3.3%), nausea (2.7%), hypotension (2.5%), headache (2.2%), and edema (1.9%). Less frequent side effects include fatigue, flushing, bradycardia, AV block, heart failure, and elevated liver enzymes. Rare but serious adverse effects include gingival hyperplasia, erythema multiforme, and parkinsonian symptoms. Most side effects are dose-dependent and often diminish with continued therapy. Constipation may be managed with appropriate dietary measures or stool softeners.

Drug interaction

Calan demonstrates significant pharmacokinetic and pharmacodynamic interactions. It potentiates effects of other antihypertensive agents, digitalis glycosides, and neuromuscular blocking agents. Concurrent use with beta-blockers may result in excessive bradycardia or heart failure. CYP3A4 inhibitors (ketoconazole, erythromycin) increase verapamil concentrations, while inducers (rifampin, phenytoin) decrease levels. Calan increases concentrations of simvastatin, lovastatin, and cyclosporine. It may reduce clearance of lithium and theophylline. Concomitant use with disopyramide or flecainide within 48 hours may cause serious negative inotropic effects.

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 double the dose to make up for a missed administration. For extended-release formulations, consistency in dosing time is particularly important to maintain stable blood concentrations. Healthcare providers should be consulted if multiple doses are missed or if uncertainty exists about proper dosing schedule.

Overdose

Verapamil overdose manifests as severe hypotension, bradycardia, conduction disturbances, and hyperglycemia. Massive overdose may lead to cardiogenic shock, metabolic acidosis, and non-cardiogenic pulmonary edema. Treatment involves gastric lavage if presented early, activated charcoal, and comprehensive supportive care. Calcium gluconate (1-3 g IV) is the primary antidote, with repeat doses as needed. Vasopressors (norepinephrine, dopamine), atropine, and glucagon may be employed. Temporary cardiac pacing may be necessary for profound bradycardia or heart block. Hemodialysis is not effective due to high protein binding.

Storage

Store at controlled room temperature (20-25°C or 68-77°F) with excursions permitted between 15-30°C (59-86°F). Protect from moisture and light. Keep in original container with tight closure. Do not store in bathroom or other areas with high humidity. Keep all medications out of reach of children and pets. Properly discard expired or unused medication through drug take-back programs or following FDA-recommended disposal methods. Do not flush medications down the toilet unless specifically instructed.

Disclaimer

This information is provided for educational purposes only and does not constitute medical advice. Individual therapeutic decisions should be made by qualified healthcare professionals based on comprehensive patient assessment. The prescribing physician should be consulted for specific dosage recommendations and treatment duration. Patients should not alter their medication regimen without professional guidance. While every effort has been made to ensure accuracy, pharmaceutical information may change, and readers are encouraged to verify details with current prescribing information.

Reviews

Clinical studies demonstrate Calan’s efficacy with 70-80% of hypertensive patients achieving blood pressure control (<140/90 mmHg) at appropriate doses. Cardiology guidelines consistently recommend calcium channel blockers like verapamil as first-line therapy for hypertension, particularly in patients with angina or certain arrhythmias. Long-term extension studies show maintained efficacy over 2-5 years of treatment with stable safety profile. Patient satisfaction surveys indicate good tolerability when properly titrated, though constipation remains the most frequently reported bothersome side effect. The extended-release formulation receives particularly positive feedback for improved adherence due to once-daily dosing.