Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
CARDIZEM LA vs ADALAT
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.
Dihydropyridine calcium channel blocker; inhibits calcium ion influx across cardiac and vascular smooth muscle cells, reducing peripheral vascular resistance and blood pressure.
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.
10-20 mg orally three times daily; extended-release: 30-60 mg orally once daily; maximum 120 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: 2-5 hours (immediate-release); 8-14 hours (extended-release). Context: shorter half-life necessitates multiple daily dosing for immediate-release; extended-release allows once-daily dosing.
Primarily hepatic via CYP3A4; undergoes extensive first-pass metabolism. Metabolites include N-desmethyl diltiazem (active), deacetyl diltiazem, and others.
Hepatic via CYP3A4; extensive first-pass metabolism; metabolites are inactive.
Urine (2-4% unchanged, ~40% as metabolites); bile/feces (major route, ~60% as metabolites).
Renal: 70-80% as metabolites; Fecal: 15-20% as metabolites; <1% unchanged in urine
70-80% bound to plasma proteins (mainly albumin).
92-98% bound to plasma proteins (albumin and alpha-1-acid glycoprotein)
3-5 L/kg, indicating extensive tissue distribution.
0.8-1.2 L/kg. Clinical meaning: indicates extensive tissue distribution, consistent with high lipophilicity.
Oral: ~40% due to extensive first-pass metabolism; intravenous: 100%.
Oral immediate-release: 45-60% (due to first-pass metabolism); extended-release: 60-85% (due to slower release and reduced first-pass effect).
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 dose adjustment required for GFR ≥30 m L/min; for GFR <30 m L/min, use with caution and reduce initial dose by 50%.
Child-Pugh A: no adjustment. Child-Pugh B: reduce dose by 50%. Child-Pugh C: use is not recommended.
Child-Pugh Class A: no adjustment; Class B: reduce dose by 50%; Class C: avoid use or reduce by 75%.
Safety and efficacy have not been established in pediatric patients; no standard pediatric dosing available.
0.25-0.5 mg/kg/dose orally every 6-8 hours; maximum 3 mg/kg/day. Extended-release not recommended.
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.
Start at 10 mg orally twice daily; titrate slowly due to increased sensitivity and risk of hypotension.
None.
None
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.
May cause hypotension, especially in patients on beta-blockers or with poor cardiac reserve,Risk of increased angina and/or myocardial infarction upon initiation or dose increase,Peripheral edema,Stevens-Johnson syndrome and toxic epidermal necrolysis (rare),Hepatic impairment,Exacerbation of angina on withdrawal
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,Cardiogenic shock,Significant aortic stenosis,Concurrent use with rifampin,Pregnancy (category C)
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.
Avoid grapefruit and grapefruit juice; they inhibit CYP3A4 and increase nifedipine serum concentrations, leading to enhanced hypotensive effects and risk of toxicity. Grapefruit interaction persists for 24 hours; separate consumption by at least 4 hours if unavoidable, but preferable to avoid entirely. Avoid alcohol which can increase hypotension. High-fat meals may reduce absorption of extended-release formulations; take consistently with or without food.
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.
First trimester: Limited human data; animal studies show embryotoxicity. Second/third trimester: May cause fetal hypoxia due to maternal hypotension; risk of preterm labor inhibition. Category C.
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.
Excreted in breast milk; M/P ratio ~0.85. Consider risks versus benefits; monitor infant for hypotension.
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.
No standard dose adjustment; monitor clinical response and blood pressure; may require lower doses due to vasodilation effects.
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.
Adalat (nifedipine) is a dihydropyridine calcium channel blocker. Use immediate-release capsules only for hypertensive emergencies, not chronic treatment due to risk of reflex tachycardia and unpredictable hypotension. Extended-release formulations are preferred for stable angina and hypertension. Avoid grapefruit juice as it increases nifedipine levels via CYP3A4 inhibition. Monitor for peripheral edema, gingival hyperplasia, and constipation. Contraindicated in cardiogenic shock, severe aortic stenosis, and within 4 weeks of myocardial infarction.
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 extended-release tablets whole; do not crush, chew, or split.,Avoid grapefruit and grapefruit juice while taking this medication.,Report persistent swelling of ankles/feet, gum tenderness or bleeding, or severe dizziness.,Do not stop abruptly; taper under medical supervision to avoid rebound hypertension.,Take at the same time each day; if a dose is missed, skip it if near next dose.,May cause dizziness; avoid driving until you know how it affects you.,Increase fluid and fiber intake to prevent constipation.,Store at room temperature away from light and moisture.
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 ADALAT, 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.. ADALAT is a Calcium Channel Blocker that works by Dihydropyridine calcium channel blocker; inhibits calcium ion influx across cardiac and vascular smooth muscle cells, reducing peripheral vascular resistance and blood pressure.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between CARDIZEM LA and ADALAT 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 ADALAT is: 10-20 mg orally three times daily; extended-release: 30-60 mg orally once daily; maximum 120 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 ADALAT 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. ADALAT is classified as Category C. First trimester: Limited human data; animal studies show embryotoxicity. Second/third trimester: May cause fetal hypoxia due to maternal hypotension; risk of preterm labor inhibiti. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.