Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
DILACOR XR 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 ion influx across cardiac and vascular smooth muscle cells, resulting in dilation of coronary and systemic arteries, decreased myocardial contractility, and reduced sinoatrial and atrioventricular 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.
Angina pectoris due to coronary artery spasm (Prinzmetal's variant angina),Chronic stable angina,Essential hypertension
Hypertension,Chronic stable angina,Vasospastic angina (Prinzmetal's angina)
180 to 240 mg orally once daily, administered on an empty stomach; maximum dose 480 mg once daily.
30 mg orally once daily; may titrate to 60 mg or 90 mg once daily based on response and tolerability.
Terminal half-life: 6-12 hours (prolonged in elderly, hepatic impairment, or with CYP3A4 inhibitors)
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.
Extensively metabolized in the liver via CYP3A4; undergoes deacetylation and N-demethylation.
Hepatic metabolism via CYP3A4; nifedipine is converted to inactive metabolites.
Renal (70% as metabolites, 3-4% as unchanged drug); biliary/fecal (25-30%)
Renal: 70-80% as metabolites, fecal: 15-20% as metabolites, biliary: minimal (<5% unchanged).
98-99% bound to serum albumin and alpha-1-acid glycoprotein
92-98% bound primarily to albumin.
1.1-1.8 L/kg (high Vd indicates extensive tissue binding)
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% (first-pass metabolism; food does not affect extent)
65-90% after oral administration; absolute bioavailability of nifedipine in ADALAT CC: approximately 65% due to first-pass metabolism in liver and gut wall.
GFR 30-60 m L/min: initiate at 120 mg once daily, titrate cautiously; GFR <30 m L/min: not recommended due to risk of accumulation.
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: initiate at 120 mg once daily; Child-Pugh Class B or C: avoid use.
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.
Safety and effectiveness in pediatric patients have not been established; no dosing recommendations.
Safety and efficacy not established; use is not recommended in pediatric patients.
Start at low end of dosing range (120 mg once daily) due to increased systemic exposure and risk of hypotension; titrate slowly.
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 hypotension, bradycardia, and heart block; avoid in patients with sick sinus syndrome or second- or third-degree AV block without a pacemaker; caution in patients with congestive heart failure; may increase risk of digitalis toxicity; abrupt withdrawal may worsen angina.
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 in presence of functioning ventricular pacemaker), second- or third-degree AV block (except with pacemaker), hypotension (systolic < 90 mm Hg), acute myocardial infarction with pulmonary congestion, hypersensitivity to diltiazem, concurrent use of ivabradine.
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 plasma concentrations, leading to increased risk of adverse effects. Avoid high-fat meals as they may affect the absorption of the extended-release formulation.
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.
DILACOR XR (diltiazem) is a calcium channel blocker with limited human pregnancy data. In animal studies, at doses up to 5 times the maximum recommended human dose, no teratogenic effects were observed. However, embryofetal toxicity (increased fetal loss, growth retardation) occurred at maternally toxic doses. First trimester: No adequate human studies; risk cannot be excluded. Second and third trimesters: Use only if clearly needed; may cause maternal hypotension and reduced uteroplacental blood flow, potentially leading to fetal hypoxia and growth restriction. U. S. FDA Pregnancy 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 breast milk. The milk-to-plasma (M/P) ratio ranges from 0.7 to 0.9. Limited data suggest infant exposure is low (approximately 1% of maternal weight-adjusted dose). No adverse effects reported in breastfed infants. Caution advised; monitor infant for bradycardia, hypotension, and sedation. Alternative agents may be preferred.
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.
Plasma volume and renal clearance increase during pregnancy, potentially reducing diltiazem concentrations. However, specific pharmacokinetic studies are lacking. Clinical response and blood pressure should guide dosing. Start at the lowest effective dose and titrate based on maternal heart rate and blood pressure. Avoid sustained-release formulations if rapid titration needed; immediate-release may be used. Monitor for hypotension, which may worsen uteroplacental perfusion. No specific dose adjustment recommended in published guidelines; use caution and individualized dosing.
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.
DILACOR XR is a sustained-release formulation of diltiazem, a calcium channel blocker. Do not crush or chew the capsule; swallowing whole is essential for extended-release properties. Monitor heart rate and blood pressure regularly due to risk of bradycardia and hypotension. Use with caution in patients with reduced hepatic function as diltiazem undergoes extensive first-pass metabolism. Avoid concurrent use with strong CYP3A4 inhibitors (e.g., ketoconazole) as they can increase diltiazem levels. In patients with atrial fibrillation or flutter, it may be used for rate control but contraindicated in sick sinus syndrome or second/third-degree AV block without a 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.
Swallow DILACOR XR capsules whole; do not crush, chew, or break them.,Take this medication exactly as prescribed, usually once daily. Do not stop suddenly without consulting your doctor.,Avoid grapefruit and grapefruit juice as they can increase the effects and side effects of diltiazem.,Limit alcohol intake as it may increase the risk of dizziness or fainting.,Notify your doctor if you experience slow heartbeat, shortness of breath, swelling of ankles/feet, or severe dizziness.,Keep a record of your blood pressure and pulse at home and bring it to appointments.,Do not take other medications, including over-the-counter products or herbal supplements, without consulting your healthcare provider.
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 DILACOR XR vs ADALAT CC, answered by our medical review team.
DILACOR XR is a Calcium Channel Blocker that works by Diltiazem inhibits calcium ion influx across cardiac and vascular smooth muscle cells, resulting in dilation of coronary and systemic arteries, decreased myocardial contractility, and reduced sinoatrial and atrioventricular 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 DILACOR XR 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 DILACOR XR is: 180 to 240 mg orally once daily, administered on an empty stomach; maximum dose 480 mg once daily.. 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 DILACOR XR 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. DILACOR XR is classified as Category C. DILACOR XR (diltiazem) is a calcium channel blocker with limited human pregnancy data. In animal studies, at doses up to 5 times the maximum recommended human dose, no teratogenic . 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.