Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
CARDIZEM vs ADALAT CC
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Diltiazem inhibits calcium influx into cardiac and vascular smooth muscle cells during depolarization by binding to L-type calcium channels. This results in coronary vasodilation, decreased myocardial oxygen demand, and negative chronotropic and inotropic effects.
Nifedipine, a dihydropyridine calcium channel blocker, inhibits calcium ion influx across cardiac and smooth muscle cell membranes, leading to vasodilation and decreased myocardial contractility.
Angina pectoris (chronic stable, vasospastic),Atrial fibrillation or atrial flutter (rate control),Hypertension
Hypertension,Chronic stable angina,Vasospastic angina (Prinzmetal's angina)
Oral: 30-120 mg three to four times daily; extended-release: 120-360 mg once daily. IV: Initial 0.25 mg/kg (max 25 mg) bolus over 2 minutes, may repeat in 15 minutes (0.35 mg/kg); maintenance: 5-15 mg/hour continuous infusion.
30 mg orally once daily; may titrate to 60 mg or 90 mg once daily based on response and tolerability.
Terminal elimination half-life is 3.0-4.5 hours in healthy adults; may be prolonged to 7-9 hours in elderly, hepatic impairment, or renal impairment; clinically relevant for dosing frequency.
Terminal elimination half-life: 7-10 hours; clinical context: sustained-release formulation provides therapeutic concentrations over 24 hours with once-daily dosing, but half-life does not directly reflect drug effect duration due to slow absorption.
Hepatic via CYP3A4; undergoes extensive first-pass metabolism; metabolites: desacetyl diltiazem (active, 40-50% potency), N-demethylated, and deacetylated forms.
Hepatic metabolism via CYP3A4; nifedipine is converted to inactive metabolites.
Primarily hepatic metabolism with extensive first-pass effect; approximately 2-4% excreted unchanged in urine; fecal excretion accounts for about 65% of dose as metabolites; renal excretion accounts for about 35% of dose as metabolites.
Renal: 70-80% as metabolites, fecal: 15-20% as metabolites, biliary: minimal (<5% unchanged).
77-87% bound to plasma proteins, primarily albumin.
92-98% bound primarily to albumin.
3-5 L/kg; large Vd indicates extensive tissue binding and distribution.
1.2-1.6 L/kg; clinical meaning: indicates extensive tissue distribution, with higher concentrations in organs such as liver and kidney, and lower in brain due to P-glycoprotein efflux.
Oral: 40-50% due to significant first-pass metabolism (range 30-60% across individuals); IV: 100%.
65-90% after oral administration; absolute bioavailability of nifedipine in ADALAT CC: approximately 65% due to first-pass metabolism in liver and gut wall.
No specific dose adjustment for renal impairment; use with caution in severe renal dysfunction (Cr Cl <30 m L/min) with close monitoring of heart rate and blood pressure.
No dose adjustment required for mild to moderate renal impairment. For severe renal impairment (Cr Cl <30 m L/min), start at 30 mg once daily and titrate cautiously.
Child-Pugh Class A: No adjustment. Class B: Reduce total daily dose by 25-50%. Class C: Avoid use; if necessary, consider further dose reduction with careful monitoring.
For mild to moderate hepatic impairment (Child-Pugh A or B), reduce initial dose to 30 mg once daily; for severe impairment (Child-Pugh C), contraindicated or use with extreme caution.
Oral: 1.5-2 mg/kg/day divided every 6-8 hours, maximum 3.5 mg/kg/day. Extended-release not recommended in children. IV: Use only with caution; dosing not well established; typical initial bolus 0.1-0.3 mg/kg over 2 minutes, maximum 10 mg; infusion 0.5-5 mcg/kg/min.
Safety and efficacy not established; use is not recommended in pediatric patients.
Start at lower end of dosing range: oral immediate-release 30 mg three times daily; extended-release 120 mg once daily. Increase slowly. IV: Lower initial bolus (0.15-0.2 mg/kg) and infusion rates (2-5 mg/hour). Monitor for hypotension and bradycardia.
Initiate at 30 mg once daily; titrate slowly due to increased risk of hypotension and higher drug exposure. Monitor closely.
There is no FDA black box warning for CARDIZEM (diltiazem).
No FDA black box warning.
Symptomatic hypotension,Bradycardia or heart block (especially in sick sinus syndrome or AV block without pacemaker),Worsening heart failure in patients with reduced ventricular function,Hepatic injury (rare but elevated liver enzymes reported),Concomitant use with beta-blockers may increase risk of bradycardia and heart failure,Digitalis toxicity risk increased when used with digoxin,May exacerbate myasthenia gravis,Acute generalized exanthematous pustulosis (AGEP) and other severe cutaneous reactions,Gradual withdrawal recommended for chronic therapy to avoid angina exacerbation,May lower blood pressure, use with caution in patients with hypotension,Use in renal impairment: monitor carefully
Beta-blocker withdrawal: taper if discontinuing; exacerbation of angina,Heart failure: use caution in patients with severe left ventricular dysfunction,Hepatic impairment: reduce dose,Peripheral edema: may occur; differentiate from worsening heart failure,Monitor blood pressure during initiation and titration
Hypersensitivity to diltiazem or any component,Sick sinus syndrome (except with functioning ventricular pacemaker),Second- or third-degree AV block (except with functioning pacemaker),Severe hypotension (systolic < 90 mm Hg),Acute myocardial infarction with pulmonary congestion,Atrial fibrillation or flutter associated with accessory bypass tract (e.g., WPW syndrome; risk of ventricular tachycardia or fibrillation),Cardiogenic shock,Concurrent use with ivabradine,Lactation (due to potential adverse effects in infants)
Hypersensitivity to nifedipine or any component,Cardiogenic shock,Concurrent use with strong CYP3A4 inducers (e.g., rifampin)
Avoid grapefruit and grapefruit juice as they inhibit CYP3A4 and can increase diltiazem levels, leading to toxicity. High-fat meals may increase absorption of some extended-release formulations; take with consistent meals. Alcohol may increase the risk of hypotension and dizziness. Maintain adequate hydration and avoid excessive salt intake to control blood pressure.
Avoid grapefruit and grapefruit juice as they inhibit CYP3A4 metabolism, raising nifedipine levels and risk of toxicity. High-fat meals may increase absorption; take consistently with respect to meals. Avoid alcohol as it may exacerbate hypotension.
No adequate studies in pregnant women. In animal studies, diltiazem (Cardizem) has been shown to cause skeletal abnormalities and increased fetal mortality at doses 5-10 times the maximum recommended human dose. Based on animal data and human experience with calcium channel blockers, risk cannot be ruled out. Use only if potential benefit justifies risk to fetus. Category C.
Adalat CC (nifedipine) is an extended-release formulation of nifedipine, a dihydropyridine calcium channel blocker. In animal studies, nifedipine has been associated with embryotoxicity, fetotoxicity, and teratogenicity (e.g., digital anomalies, cleft palate) at doses several times the maximum recommended human dose. In humans, data are limited but there is no clear evidence of a significant increase in major congenital malformations. First trimester exposure is not strongly associated with major defects; however, some studies suggest a possible small increase in oral clefts. Second and third trimester use may cause maternal hypotension and subsequent fetal distress (e.g., reduced uteroplacental perfusion). Use near term may theoretically inhibit labor, but nifedipine is used as a tocolytic for preterm labor. Overall, the risk is considered low; however, fetal monitoring is recommended if used in pregnancy. FDA Pregnancy Category C (prior to 2015 categorization).
Diltiazem is excreted in human milk. A study reported a milk-to-plasma (M/P) ratio of approximately 0.9. The estimated infant dose is 1-2% of maternal weight-adjusted dose. Caution is advised; consider waiting 3-4 hours after dose before breastfeeding to minimize exposure.
Nifedipine is excreted into human breast milk in small amounts. The milk-to-plasma (M/P) ratio is approximately 0.56 to 1.0 based on limited data. The estimated daily infant dose via milk is less than 5% of the maternal weight-adjusted dose, which is considered clinically insignificant. No adverse effects have been reported in breastfed infants. However, caution is advised, especially with high maternal doses or prolonged use. The American Academy of Pediatrics considers nifedipine compatible with breastfeeding.
Increased plasma volume and altered protein binding in pregnancy may reduce diltiazem concentrations; consider dose titration based on clinical response. No specific dose adjustment established; monitor therapeutic effect.
Pregnancy may alter the pharmacokinetics of nifedipine due to increased plasma volume and altered hepatic metabolism. However, specific dosing adjustments for Adalat CC in pregnancy are not well established. In clinical practice, dosing for hypertension in pregnancy (e.g., preeclampsia) often uses immediate-release nifedipine, not extended-release. For Adalat CC, the same dosing as in non-pregnant adults (30-90 mg once daily) is typically used, but titration should be cautious to avoid maternal hypotension. No formal dose adjustment is recommended, but careful monitoring and individualized titration are advised.
Cardizem (diltiazem) is a non-dihydropyridine calcium channel blocker used for hypertension, angina, and atrial fibrillation/atrial flutter. It is contraindicated with IV beta-blockers due to risk of bradycardia and heart block. In AF, use IV form for rate control but avoid in WPW due to risk of ventricular pre-excitation. Diltiazem is metabolized by CYP3A4; caution with strong inhibitors like clarithromycin or grapefruit juice. For hypertension, start at 30 mg TID or extended-release once daily. Monitor heart rate and PR interval; avoid in sick sinus syndrome or second/third-degree AV block without pacemaker.
Adalat CC (nifedipine extended-release) is a dihydropyridine calcium channel blocker used primarily for hypertension. Avoid in patients with unstable angina or within 4 weeks of myocardial infarction due to reflex tachycardia risk. May cause peripheral edema, especially in higher doses; consider adding an ACE inhibitor if edema is problematic. CYP3A4 inhibitors (e.g., grapefruit juice, macrolides, azole antifungals) significantly increase nifedipine levels; avoid coadministration. Tablet shell may appear intact in stool; this is normal.
Take this medication exactly as prescribed; do not crush or chew extended-release capsules.,Avoid grapefruit and grapefruit juice while taking this medication.,If you miss a dose, take it as soon as you remember unless it is almost time for your next dose; do not double the dose.,Do not stop taking this medication abruptly, as it may worsen your condition.,Common side effects include dizziness, headache, and swelling in the ankles/feet; contact your doctor if you experience slow heartbeat, shortness of breath, or fainting.,This medication may cause dizziness or lightheadedness; avoid driving or operating machinery until you know how it affects you.
Swallow the tablet whole; do not crush or chew.,Do not consume grapefruit or grapefruit juice while taking this medication.,May cause dizziness or lightheadedness; avoid driving if affected.,Notify your doctor if you experience rapid heartbeat, swelling in the ankles or feet, or prolonged erections.,Take exactly as prescribed; do not skip doses or stop abruptly without consulting your doctor.
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 vs ADALAT CC, answered by our medical review team.
CARDIZEM is a Calcium Channel Blocker that works by Diltiazem inhibits calcium influx into cardiac and vascular smooth muscle cells during depolarization by binding to L-type calcium channels. This results in coronary vasodilation, decreased myocardial oxygen demand, and negative chronotropic and inotropic effects.. ADALAT CC is a Calcium Channel Blocker that works by Nifedipine, a dihydropyridine calcium channel blocker, inhibits calcium ion influx across cardiac and smooth muscle cell membranes, leading to vasodilation and decreased myocardial contractility.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between CARDIZEM and ADALAT CC 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 is: Oral: 30-120 mg three to four times daily; extended-release: 120-360 mg once daily. IV: Initial 0.25 mg/kg (max 25 mg) bolus over 2 minutes, may repeat in 15 minutes (0.35 mg/kg); maintenance: 5-15 mg/hour continuous infusion.. The standard adult dose of ADALAT CC is: 30 mg orally once daily; may titrate to 60 mg or 90 mg once daily based on response and tolerability.. 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 and ADALAT CC 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 is classified as Category C. No adequate studies in pregnant women. In animal studies, diltiazem (Cardizem) has been shown to cause skeletal abnormalities and increased fetal mortality at doses 5-10 times the . ADALAT CC is classified as Category C. Adalat CC (nifedipine) is an extended-release formulation of nifedipine, a dihydropyridine calcium channel blocker. In animal studies, nifedipine has been associated with embryotox. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.