Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
CARDIZEM LA vs AFEDITAB CR
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Cardizem LA (diltiazem) is a calcium channel blocker that inhibits calcium ion influx across cardiac and smooth muscle cells during depolarization, leading to negative inotropic, chronotropic, and dromotropic effects. It dilates coronary and peripheral arteries, reducing systemic vascular resistance and myocardial oxygen demand.
Nifedipine is a dihydropyridine calcium channel blocker that inhibits the influx of calcium ions through L-type channels in vascular smooth muscle and cardiac muscle, leading to vasodilation and reduced myocardial contractility.
Hypertension,Chronic stable angina pectoris,Atrial fibrillation or atrial flutter (rate control),Paroxysmal supraventricular tachycardia (PSVT)
Hypertension,Chronic stable angina,Vasospastic angina (Prinzmetal's angina)
Oral, 180-360 mg once daily; initiate at 180 mg once daily, titrate to 240 mg, then 300 mg, then 360 mg once daily as needed.
30-60 mg orally once daily, extended-release; maximum 90 mg/day.
Terminal elimination half-life: 5-8 hours after oral administration. For extended-release formulations, the half-life is similar but the prolonged absorption phase results in sustained plasma concentrations.
Terminal elimination half-life is 6-11 hours; prolonged in hepatic impairment and elderly due to reduced clearance
Primarily hepatic via CYP3A4; undergoes extensive first-pass metabolism. Metabolites include N-desmethyl diltiazem (active), deacetyl diltiazem, and others.
Primarily hepatic via CYP3A4; undergoes extensive first-pass metabolism.
Urine (2-4% unchanged, ~40% as metabolites); bile/feces (major route, ~60% as metabolites).
Renal (80% as inactive metabolites), fecal (15% as metabolites), unchanged drug (<1%)
70-80% bound to plasma proteins (mainly albumin).
92-98% bound to plasma proteins (primarily albumin)
3-5 L/kg, indicating extensive tissue distribution.
0.5-0.9 L/kg; high distribution indicates extensive tissue binding
Oral: ~40% due to extensive first-pass metabolism; intravenous: 100%.
Oral extended-release: approximately 50-60% due to first-pass metabolism; absolute bioavailability is 45-60%
No specific dose adjustment is required for decreased GFR; however, use with caution in severe renal impairment (Cr Cl <30 m L/min) due to potential accumulation.
No adjustment required for any degree of renal impairment, but use with caution in patients with severe renal failure due to risk of hypotension.
Child-Pugh A: no adjustment. Child-Pugh B: reduce dose by 50%. Child-Pugh C: use is not recommended.
Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 50%; Child-Pugh C: contraindicated.
Safety and efficacy have not been established in pediatric patients; no standard pediatric dosing available.
Not recommended for use in pediatric patients; safety and efficacy not established.
Initiate at low end of dosing range (180 mg once daily) and titrate slowly due to increased risk of hypotension, bradycardia, and reduced hepatic clearance.
Initiate at lower end of dosing range (30 mg once daily) due to increased sensitivity to hypotensive effects and potential for reduced hepatic clearance.
None.
No FDA black box warning.
Conduction abnormalities: May worsen sinus node dysfunction or AV block, especially in elderly or with beta-blockers.,Heart failure: Use with caution in patients with reduced left ventricular function.,Hypotension: May cause symptomatic hypotension, especially with concurrent vasodilators.,Hepatic impairment: Diltiazem is hepatically metabolized; use with caution in patients with hepatic impairment.,Abrupt withdrawal: May precipitate angina or hypertension exacerbation; taper dose.,Beta-blocker coadministration: Increased risk of bradycardia, AV block, and hypotension.
Hypotension, especially with immediate-release formulations,Peripheral edema,Hepatic impairment,Increased angina/acute MI upon withdrawal or dose escalation,Beta-blocker withdrawal,Congestive heart failure
Sick sinus syndrome (unless pacemaker present),Second- or third-degree AV block (unless pacemaker present),Systolic blood pressure <90 mm Hg,Acute myocardial infarction with pulmonary congestion,Known hypersensitivity to diltiazem,Concurrent use with rifampin (enzyme inducer reduces effectiveness)
Hypersensitivity to nifedipine or any component,Cardiogenic shock,Concomitant use with strong CYP3A4 inducers (e.g., rifampin),Kock pouch (ileostomy)
Avoid grapefruit and grapefruit juice as they inhibit CYP3A4 and may increase diltiazem levels. Limit alcohol intake due to additive vasodilation and hypotension risk. No specific food restrictions otherwise, but maintain a heart-healthy diet low in sodium and saturated fats to support blood pressure and angina management.
Grapefruit juice increases nifedipine levels via CYP3A4 inhibition; avoid consumption. High-fat meals may delay absorption but do not alter overall exposure. Avoid alcohol as it can exacerbate vasodilation and hypotension.
Category C. First trimester: No adequate studies in humans; animal studies show embryotoxicity and fetotoxicity at high doses. Second and third trimesters: Risk of fetal bradycardia, hypotension, and growth restriction; avoid use if possible.
Teratogenic effects not established; first trimester: no data in humans, animal studies show no teratogenicity; second and third trimesters: risk of fetal hypoxia, intrauterine growth restriction (IUGR), and oligohydramnios; may cause neonatal hypotension, bradycardia, and hypoglycemia if used near term. Contraindicated in pregnancy for hypertension; use only if benefit outweighs risk (e.g., tocolysis).
Diltiazem is excreted in breast milk; M/P ratio not established. Limited data suggest low levels; however, monitor infant for bradycardia, hypotension, and feeding difficulties. Use with caution.
Nifedipine excreted into breast milk; M/P ratio approximately 0.42-0.77; limited human data; no adverse effects reported in infants; use with caution during breastfeeding.
No standard dose adjustment; pharmacokinetic changes (increased volume of distribution, altered protein binding) may necessitate titration based on clinical response. Avoid in first trimester if possible.
Plasma clearance may increase due to higher volume of distribution and metabolism; no specific dose adjustment recommended; titrate based on maternal blood pressure and response; avoid around labor due to tocolytic effect.
CARDIZEM LA is a once-daily extended-release formulation of diltiazem, a non-dihydropyridine calcium channel blocker. It is useful for hypertension and chronic stable angina. Avoid use in patients with second- or third-degree AV block, sick sinus syndrome without pacemaker, hypotension (SBP <90 mm Hg), or acute MI with pulmonary congestion. Monitor heart rate and PR interval, as it can cause bradycardia and AV block. Contraindicated with IV beta-blockers; caution with oral beta-blockers due to additive negative chronotropic effects. CYP3A4 substrate; avoid strong inhibitors/inducers. Do not crush or chew capsules; can sprinkle contents on applesauce for patients with swallowing difficulties. Max antihypertensive effect may take 2 weeks. Withdrawal may cause angina exacerbation; taper if discontinuing. Use with caution in heart failure with reduced ejection fraction (HFr EF) due to negative inotropic effects.
AFEDITAB CR is a controlled-release formulation of nifedipine, a dihydropyridine calcium channel blocker. Avoid grapefruit juice as it inhibits CYP3A4 metabolism, increasing nifedipine levels. Use cautiously in patients with aortic stenosis or left ventricular dysfunction due to risk of hypotension. Do not crush or chew tablets; intact shell may appear in stool.
Take exactly as prescribed, usually once daily. Swallow capsule whole; do not crush or chew. If you have trouble swallowing, you may open the capsule and sprinkle the beads on a spoonful of applesauce; swallow immediately without chewing.,This medication helps lower blood pressure and reduce chest pain (angina). It may take up to 2 weeks to see the full effect on blood pressure. Keep taking it even if you feel well.,Avoid drinking grapefruit juice or eating grapefruit while taking this medication as it can increase side effects.,Common side effects include swelling in legs/ankles, headache, dizziness, or flushing. Report slow heartbeat, severe dizziness, fainting, or shortness of breath to your doctor.,Do not stop taking this medication suddenly, as it may worsen chest pain or cause a heart attack. Your doctor will tell you how to taper the dose if needed.,Limit alcohol consumption, as it may increase dizziness or lower blood pressure further.,Inform all healthcare providers you are taking CARDIZEM LA, especially before surgery or dental procedures.
Swallow the tablet whole; do not crush, chew, or break it.,Avoid grapefruit juice while taking this medication.,Do not discontinue abruptly; taper under medical supervision.,Report symptoms of hypotension like dizziness or fainting.,Limit alcohol intake as it may worsen side effects.,Monitor for fluid retention (ankle swelling) and notify doctor if worsening.
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 CARDIZEM LA vs AFEDITAB CR, answered by our medical review team.
CARDIZEM LA is a Calcium Channel Blocker that works by Cardizem LA (diltiazem) is a calcium channel blocker that inhibits calcium ion influx across cardiac and smooth muscle cells during depolarization, leading to negative inotropic, chronotropic, and dromotropic effects. It dilates coronary and peripheral arteries, reducing systemic vascular resistance and myocardial oxygen demand.. AFEDITAB CR is a Calcium Channel Blocker that works by Nifedipine is a dihydropyridine calcium channel blocker that inhibits the influx of calcium ions through L-type channels in vascular smooth muscle and cardiac muscle, leading to vasodilation and reduced myocardial contractility.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between CARDIZEM LA and AFEDITAB CR 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 CARDIZEM LA is: Oral, 180-360 mg once daily; initiate at 180 mg once daily, titrate to 240 mg, then 300 mg, then 360 mg once daily as needed.. The standard adult dose of AFEDITAB CR is: 30-60 mg orally once daily, extended-release; maximum 90 mg/day.. 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 CARDIZEM LA and AFEDITAB CR 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. CARDIZEM LA is classified as Category C. Category C. First trimester: No adequate studies in humans; animal studies show embryotoxicity and fetotoxicity at high doses. Second and third trimesters: Risk of fetal bradycardi. AFEDITAB CR is classified as Category C. Teratogenic effects not established; first trimester: no data in humans, animal studies show no teratogenicity; second and third trimesters: risk of fetal hypoxia, intrauterine gro. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.