Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
CARDENE SR vs CALAN
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Nicardipine is a dihydropyridine calcium channel blocker that inhibits the transmembrane influx of calcium ions into vascular smooth muscle and cardiac muscle. It produces relaxation of coronary vascular smooth muscle and dilation of coronary arteries, and also dilates peripheral arteries, reducing systemic vascular resistance and blood pressure.
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: 30 mg orally twice daily (SR capsules). Titrate up to 60 mg twice daily. Usual maintenance: 30-60 mg twice daily.
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 8.6 hours (range 6-15 hours). Clinical context: No accumulation at steady state with TID dosing.
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 cytochrome P450 (CYP3A4) isoenzyme.
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: 60% (metabolites, unchanged drug <1%); Biliary/Fecal: 35%
Approximately 70% renal (3-4% unchanged, remainder as metabolites) and 25% biliary/fecal.
95-98%, primarily to albumin and alpha-1-acid glycoprotein
Approximately 90% bound to plasma proteins, primarily albumin.
0.3-0.7 L/kg. Clinical meaning: Indicates extensive tissue distribution.
Vd 4-5 L/kg; indicates extensive tissue distribution beyond plasma volume.
Oral: 35% (first-pass metabolism); Food does not significantly affect bioavailability.
Oral bioavailability is 20-35% due to extensive first-pass hepatic metabolism; IV bioavailability is 100%.
No specific GFR-based dose adjustment provided by manufacturer; use with caution in renal impairment, especially if concurrent hepatic impairment.
Cr Cl <30 m L/min: reduce dose by 50% and monitor carefully.
Child-Pugh Class A: No adjustment. Child-Pugh Class B/C: Consider starting at 15 mg twice daily and titrate slowly due to increased bioavailability.
Child-Pugh A: 50% of normal dose; Child-Pugh B: 25% of normal dose; Child-Pugh C: contraindicated or use with extreme caution.
Not established; safety and efficacy in pediatric patients have not been determined.
Oral: 4-8 mg/kg/day in 3 divided doses; IV: 0.1-0.3 mg/kg over 2 minutes, max 5 mg.
Start at lower initial dose (15 mg twice daily) and titrate cautiously due to increased bioavailability and slower elimination.
Start at lowest dose (e.g., 40 mg 3 times daily) and titrate slowly; monitor for hypotension and bradycardia.
None.
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).
Use caution in patients with coronary artery disease; may cause increased angina or acute myocardial infarction upon initiation or dose titration. Also caution in patients with congestive heart failure, hepatic impairment, or renal impairment. Monitor blood pressure during titration.
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 nicardipine or any component; advanced aortic stenosis.
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.
Grapefruit and grapefruit juice increase nicardipine serum concentrations by inhibiting CYP3A4 metabolism. Avoid concurrent use. High-fat meals may increase absorption; take consistently with regard to meals. Alcohol may enhance hypotensive effects; limit intake.
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.
Nifedipine, the active ingredient in Cardene SR, is classified as FDA Pregnancy Category C. There are no adequate and well-controlled studies in pregnant women. In animal studies, nifedipine has been shown to cause embryotoxicity, placentotoxicity, and fetotoxicity at doses several times the maximum recommended human dose. First trimester: Risk cannot be ruled out; potential for teratogenic effects based on animal data. Second and third trimesters: May cause maternal hypotension and fetal distress due to placental hypoperfusion; use only if benefit outweighs risk. Case reports of fetal distress, perinatal asphyxia, and cesarean delivery associated with use in preterm labor.
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.
Nifedipine is excreted into human breast milk. The milk-to-plasma ratio (M/P) is approximately 1.0. Limited data suggest infant doses are low (less than 5% of maternal weight-adjusted dose). However, due to potential for adverse effects in infants (e.g., hypotension), caution is advised. Use only if clearly needed and monitor infant for bradycardia and hypotension.
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.
Pregnancy does not necessitate routine dose adjustment of oral nifedipine. However, due to increased plasma volume and clearance in pregnancy, lower doses may be effective for hypertension. For tocolysis (off-label), dosing regimens vary (e.g., 10-20 mg oral immediate-release every 4-6 hours). Monitor for hypotension; dose should be individualized based on blood pressure 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.
CARDENE SR (nicardipine) is a dihydropyridine calcium channel blocker used for hypertension. Avoid in advanced aortic stenosis due to risk of reduced coronary perfusion. Monitor for peripheral edema, especially in elderly. Use caution in heart failure with reduced ejection fraction due to negative inotropic effects (though less than verapamil). May increase cyclosporine levels; monitor levels. For IV use (not SR), titrate rapidly for hypertensive emergency. Do not crush or chew SR capsules.
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.
Take exactly as prescribed, usually twice daily. Swallow SR capsules whole; do not crush or chew.,Avoid grapefruit and grapefruit juice as they can increase drug levels and side effects.,May cause dizziness or lightheadedness; avoid driving until you know how you react. Rise slowly from sitting or lying.,Notify your doctor if you experience swelling in ankles or feet, rapid heartbeat, or shortness of breath.,Do not stop abruptly; sudden withdrawal may worsen chest pain or blood pressure.,Keep a daily blood pressure log to track effectiveness.
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 CARDENE SR vs CALAN, answered by our medical review team.
CARDENE SR is a Calcium Channel Blocker that works by Nicardipine is a dihydropyridine calcium channel blocker that inhibits the transmembrane influx of calcium ions into vascular smooth muscle and cardiac muscle. It produces relaxation of coronary vascular smooth muscle and dilation of coronary arteries, and also dilates peripheral arteries, reducing systemic vascular resistance and blood pressure.. 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 CARDENE SR 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 CARDENE SR is: Initial: 30 mg orally twice daily (SR capsules). Titrate up to 60 mg twice daily. Usual maintenance: 30-60 mg twice daily.. 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 CARDENE SR 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. CARDENE SR is classified as Category C. Nifedipine, the active ingredient in Cardene SR, is classified as FDA Pregnancy Category C. There are no adequate and well-controlled studies in pregnant women. In animal studies, . 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.