Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
DILTZAC 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 is a calcium channel blocker that inhibits calcium ion influx across cardiac and vascular smooth muscle cells, resulting in dilation of coronary and systemic arteries and decreased myocardial contractility and conduction velocity.
Nifedipine, a dihydropyridine calcium channel blocker, inhibits calcium ion influx across cardiac and smooth muscle cell membranes, leading to vasodilation and decreased myocardial contractility.
Hypertension,Chronic stable angina,Atrial fibrillation or flutter,Paroxysmal supraventricular tachycardia,Off-label: Prevention of migraine, Raynaud's phenomenon
Hypertension,Chronic stable angina,Vasospastic angina (Prinzmetal's angina)
Oral: 30-120 mg 3-4 times daily; maximum 480 mg/day. IV: 0.25 mg/kg over 2 min, then 0.35 mg/kg after 15 min if needed; continuous infusion 5-15 mg/hour.
30 mg orally once daily; may titrate to 60 mg or 90 mg once daily based on response and tolerability.
Terminal elimination half-life: 3.5-5.0 hours (healthy adults). Prolonged in elderly (6-8 hours) and in hepatic impairment (10-12 hours).
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
Hepatic metabolism via CYP3A4; nifedipine is converted to inactive metabolites.
Renal: 60-70% as metabolites, 2-4% unchanged; Biliary/Fecal: 20-30% as metabolites.
Renal: 70-80% as metabolites, fecal: 15-20% as metabolites, biliary: minimal (<5% unchanged).
80-85% bound to plasma proteins (albumin and alpha-1-acid glycoprotein).
92-98% bound primarily to albumin.
5-6 L/kg (suggests extensive tissue 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 immediate-release: 40-60% (due to extensive first-pass hepatic metabolism). Extended-release: 30-40%. Intravenous: 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 adjustment required for GFR >30 m L/min. For GFR 10-30 m L/min, reduce dose by 25%. For GFR <10 m L/min, reduce dose by 50%.
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 A: no adjustment. Child-Pugh B: reduce dose by 50%. Child-Pugh C: reduce dose by 75%.
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: 1-3 mg/kg/day divided 3-4 times; maximum 3 mg/kg/day. IV: 0.25 mg/kg over 2 min; may repeat 0.35 mg/kg after 15 min; infusion 5-15 mcg/kg/min.
Safety and efficacy not established; use is not recommended in pediatric patients.
Start at lowest dose (30 mg 3-4 times daily) due to increased bioavailability and reduced clearance; titrate slowly. IV dose: 0.2 mg/kg over 2 min.
Initiate at 30 mg once daily; titrate slowly due to increased risk of hypotension and higher drug exposure. Monitor closely.
None.
No FDA black box warning.
May cause heart block, bradycardia, exacerbation of heart failure, hypotension, and hepatotoxicity. Monitor liver function, ECG, and blood pressure. Avoid abrupt discontinuation; taper gradually.
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
Sick sinus syndrome (except with pacemaker), second- or third-degree AV block (except with pacemaker), hypotension (systolic <90 mm Hg), cardiogenic shock, acute myocardial infarction with pulmonary congestion, hypersensitivity to diltiazem, concomitant use of ivabradine, and concurrent use with strong CYP3A4 inhibitors when diltiazem is given intravenously.
Hypersensitivity to nifedipine or any component,Cardiogenic shock,Concurrent use with strong CYP3A4 inducers (e.g., rifampin)
Avoid grapefruit and grapefruit juice; they may increase diltiazem levels and risk of side effects. Alcohol may enhance blood pressure-lowering effects and cause dizziness. A high-fat meal may increase absorption, but this is not clinically significant.
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.
First trimester: No definitive evidence of teratogenicity in animal studies; human data limited. Second and third trimesters: Chronic use may cause fetal bradycardia, hypoxia, and growth restriction due to maternal hypotension and reduced placental perfusion.
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 breast milk with low levels. Milk-to-plasma ratio is approximately 0.28. Caution advised; monitor infant for bradycardia and hypotension.
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.
No standard dose adjustment required; however, increased plasma volume may reduce drug levels. Titrate to therapeutic effect with careful blood pressure monitoring.
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.
Diltzac is a calcium channel blocker (diltiazem) used for hypertension, angina, and atrial fibrillation. Avoid in patients with sick sinus syndrome (without pacemaker), second/third-degree AV block, or severe hypotension. Use with caution in hepatic impairment and renal failure. Monitor heart rate and ECG for bradycardia. Adjust dose with CYP3A4 inhibitors (e.g., grapefruit) or inducers. Advise gradual withdrawal to avoid rebound hypertension.
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 exactly as prescribed; do not stop abruptly or change dose without consulting your doctor.,Avoid grapefruit and grapefruit juice while taking Diltzac.,Do not drive or operate heavy machinery if you experience dizziness or lightheadedness.,Monitor for signs of heart failure (swelling of ankles, feet, or sudden weight gain) and report immediately.,Your doctor may need to do regular blood tests to check liver function and monitor your heart rate and blood pressure.
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 DILTZAC vs ADALAT CC, answered by our medical review team.
DILTZAC is a Calcium Channel Blocker that works by Diltiazem is a calcium channel blocker that inhibits calcium ion influx across cardiac and vascular smooth muscle cells, resulting in dilation of coronary and systemic arteries and decreased myocardial contractility and conduction velocity.. 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 DILTZAC 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 DILTZAC is: Oral: 30-120 mg 3-4 times daily; maximum 480 mg/day. IV: 0.25 mg/kg over 2 min, then 0.35 mg/kg after 15 min if needed; continuous infusion 5-15 mg/hour.. 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 DILTZAC 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. DILTZAC is classified as Category C. First trimester: No definitive evidence of teratogenicity in animal studies; human data limited. Second and third trimesters: Chronic use may cause fetal bradycardia, hypoxia, and . 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.