Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
PLENDIL vs CALAN
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Dihydropyridine calcium channel blocker that inhibits calcium ion influx across cardiac and vascular smooth muscle cells, leading to vasodilation and reduced peripheral vascular resistance.
Verapamil inhibits calcium ion influx through voltage-gated L-type calcium channels in cardiac and vascular smooth muscle, leading to decreased myocardial contractility, slowed AV conduction, and vasodilation.
Hypertension,Chronic stable angina
Angina pectoris (chronic stable, vasospastic, unstable),Essential hypertension,Supraventricular tachyarrhythmias (e.g., atrial fibrillation, atrial flutter, PSVT)
Initial: 5 mg orally once daily. Maintenance: 2.5–10 mg orally once daily. Maximum: 10 mg/day.
Initial: 80-120 mg orally 3 times daily; maintenance: 240-480 mg/day in 3-4 divided doses. IV: 5-10 mg over 2 minutes, may repeat after 15-30 minutes.
Terminal elimination half-life 2-5 hours in healthy adults; 7-12 hours in patients with hepatic impairment or advanced age
Terminal elimination half-life is 3-7 hours for immediate-release; can be prolonged to 12-16 hours with sustained-release due to slow absorption; increased in hepatic impairment.
Primarily hepatic via CYP3A4; undergoes extensive first-pass metabolism.
Extensively metabolized in the liver via CYP3A4, CYP1A2, and CYP2C8 isoenzymes; undergoes N-dealkylation and O-demethylation; first-pass metabolism results in low bioavailability (20-35%).
Renal (approximately 70% as metabolites, <0.5% unchanged); fecal (approximately 10%)
Approximately 70% renal (3-4% unchanged, remainder as metabolites) and 25% biliary/fecal.
>99% bound, primarily to albumin and alpha1-acid glycoprotein
Approximately 90% bound to plasma proteins, primarily albumin.
4-10 L/kg; large Vd indicates extensive tissue distribution
Vd 4-5 L/kg; indicates extensive tissue distribution beyond plasma volume.
Oral: 15-20% (extensive first-pass metabolism)
Oral bioavailability is 20-35% due to extensive first-pass hepatic metabolism; IV bioavailability is 100%.
No adjustment required for any degree of renal impairment.
Cr Cl <30 m L/min: reduce dose by 50% and monitor carefully.
Child-Pugh A or B: Initial dose 2.5 mg orally once daily. Child-Pugh C: Contraindicated or not recommended.
Child-Pugh A: 50% of normal dose; Child-Pugh B: 25% of normal dose; Child-Pugh C: contraindicated or use with extreme caution.
Safety and efficacy not established in pediatric patients.
Oral: 4-8 mg/kg/day in 3 divided doses; IV: 0.1-0.3 mg/kg over 2 minutes, max 5 mg.
Initial dose 2.5 mg orally once daily; titrate cautiously due to increased systemic exposure.
Start at lowest dose (e.g., 40 mg 3 times daily) and titrate slowly; monitor for hypotension and bradycardia.
No FDA black box warning.
Contains verapamil hydrochloride. Risk of serious adverse effects including hypotension, bradycardia, AV block, and cardiac arrest. Must not be administered to patients with severe left ventricular dysfunction, cardiogenic shock, or sick sinus syndrome (unless paced).
Beta-blocker withdrawal: taper gradually,Peripheral edema,Hepatic impairment,Grapefruit juice increases drug levels
May cause hypotension, bradycardia, AV block, and exacerbation of heart failure. Avoid in patients with pre-existing conduction abnormalities. Use caution with beta-blockers, digoxin, and CYP3A4 inhibitors. Abrupt withdrawal may exacerbate angina. May increase lithium and carbamazepine levels.
Hypersensitivity to felodipine or any component
Severe left ventricular dysfunction, cardiogenic shock, sick sinus syndrome (without pacemaker), second- or third-degree AV block (without pacemaker), atrial flutter/fibrillation with accessory bypass tract (e.g., WPW syndrome), concurrent use of IV beta-blockers.
Avoid grapefruit and grapefruit juice as they increase felodipine plasma concentrations; take on an empty stomach or with a light meal to minimize fluctuations; high-fat meals may increase absorption.
Avoid grapefruit and grapefruit juice as they inhibit CYP3A4 metabolism, increasing verapamil levels and risk of toxicity. Limit alcohol intake as it may enhance hypotensive effects. High-fat meals may delay absorption but not extent; take consistently with regard to meals.
Pregnancy Category C. First trimester: No adequate studies in humans; animal studies show fetal toxicity at high doses. Second and third trimesters: Potential for fetal hypotension, hypoxia, and growth restriction due to maternal hypotension; avoid use if possible.
First trimester: No increased risk of major malformations observed in human studies; animal studies show fetal toxicity at high doses. Second and third trimesters: May cause fetal bradycardia, hypotension, and impaired placental perfusion; avoid use for pregnancy-induced hypertension due to risk of fetal hypoxia.
Excreted in breast milk; M/P ratio unknown. Insufficient data to determine risk; manufacturer recommends discontinuing nursing or drug due to potential for serious adverse reactions in infant.
Verapamil (CALAN) is excreted into breast milk; M/P ratio approximately 0.6. The relative infant dose is low (estimated <5% of maternal weight-adjusted dose). No adverse effects reported in breastfed infants. Caution in preterm infants or those with renal impairment.
Increased clearance of felodipine in pregnancy may necessitate dose adjustments; however, limited data prevent specific recommendations. Use lowest effective dose and monitor clinical response.
Pregnancy may increase clearance of verapamil; monitoring of therapeutic effect advised. Dose may need adjustment based on clinical response. Avoid use in pregnancy-induced hypertension.
Avoid grapefruit products; titrate slowly to minimize reflex tachycardia; use with caution in severe aortic stenosis; may cause peripheral edema, more common in women; administer extended-release tablets whole, do not crush or chew.
Calan (verapamil) is a class IV antiarrhythmic and calcium channel blocker. Use caution in patients with hepatic impairment due to reduced clearance; dose adjustment may be needed. Avoid in patients with pre-existing bradycardia, second- or third-degree AV block, or sick sinus syndrome unless a pacemaker is present. May increase digoxin levels; monitor digoxin concentrations. Use with caution in patients with hypertrophic cardiomyopathy. For IV administration, have calcium gluconate available to reverse hypotension or bradycardia. Not recommended for use in acute myocardial infarction or cardiogenic shock.
Swallow the tablet whole; do not crush, chew, or split.,Avoid grapefruit juice and grapefruit products while taking this medication.,Do not stop taking suddenly without consulting your physician.,May cause dizziness or lightheadedness; avoid driving if affected.,Report any persistent swelling of ankles or feet, severe dizziness, or irregular heartbeat.
Take exactly as prescribed; do not skip doses or stop abruptly without consulting your doctor.,Avoid grapefruit juice as it can increase verapamil levels and risk of side effects.,If you miss a dose, take it as soon as you remember unless it is almost time for the next dose; do not double the dose.,Avoid alcohol as it may worsen side effects like dizziness or low blood pressure.,Report symptoms of bradycardia (slow heart rate), palpitations, shortness of breath, or swelling of ankles/feet.,This medication may cause dizziness; avoid driving or operating machinery until you know how it affects you.,Do not consume grapefruit or its juice during treatment.,Keep a regular medication schedule and do not change brands without doctor approval.
No interactions on record
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about PLENDIL vs CALAN, answered by our medical review team.
PLENDIL is a Calcium Channel Blocker that works by Dihydropyridine calcium channel blocker that inhibits calcium ion influx across cardiac and vascular smooth muscle cells, leading to vasodilation and reduced peripheral vascular resistance.. CALAN is a Calcium Channel Blocker that works by Verapamil inhibits calcium ion influx through voltage-gated L-type calcium channels in cardiac and vascular smooth muscle, leading to decreased myocardial contractility, slowed AV conduction, and vasodilation.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between PLENDIL and CALAN depend on the specific clinical indication. These are both Calcium Channel Blocker agents and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of PLENDIL is: Initial: 5 mg orally once daily. Maintenance: 2.5–10 mg orally once daily. Maximum: 10 mg/day.. The standard adult dose of CALAN is: Initial: 80-120 mg orally 3 times daily; maintenance: 240-480 mg/day in 3-4 divided doses. IV: 5-10 mg over 2 minutes, may repeat after 15-30 minutes.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between PLENDIL and CALAN in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. PLENDIL is classified as Category C. Pregnancy Category C. First trimester: No adequate studies in humans; animal studies show fetal toxicity at high doses. Second and third trimesters: Potential for fetal hypotension. CALAN is classified as Category C. First trimester: No increased risk of major malformations observed in human studies; animal studies show fetal toxicity at high doses. Second and third trimesters: May cause fetal . Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.