Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
CARTIA XT vs CADUET
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Diltiazem, a benzothiazepine calcium channel blocker, inhibits calcium ion influx across cardiac and vascular smooth muscle cells during depolarization, leading to vasodilation and reduced myocardial contractility and conduction velocity, particularly at the AV node.
Amlodipine: Dihydropyridine calcium channel blocker that inhibits calcium ion influx across cardiac and vascular smooth muscle cell membranes, causing vasodilation and reduced peripheral vascular resistance. Atorvastatin: HMG-Co A reductase inhibitor that competitively inhibits the conversion of HMG-Co A to mevalonate, reducing cholesterol synthesis in the liver.
FDA-approved: hypertension,FDA-approved: chronic stable angina,FDA-approved: atrial fibrillation or flutter (rate control),Off-label: prevention of migraine,Off-label: anal fissure (topical)
Hypertension,Coronary artery disease,Hyperlipidemia (as adjunct to diet to reduce elevated total-C, LDL-C, apo B, and TG levels, and to increase HDL-C),Prevention of cardiovascular events in patients with multiple risk factors
Diltiazem hydrochloride extended-release capsules (CARTIA XT) are administered orally. For hypertension and angina, the typical adult dose is 180–360 mg once daily, initially 180 mg once daily, titrated to response.
CADUET (amlodipine/atorvastatin) is available as tablets of 2.5/10, 2.5/20, 2.5/40, 5/10, 5/20, 5/40, 5/80, 10/10, 10/20, 10/40, and 10/80 mg amlodipine/atorvastatin. Initial dose depends on current antihypertensive and lipid-lowering therapy. Usual starting dose is 5/10 mg orally once daily; titrate at intervals of 2-4 weeks based on blood pressure and LDL-C goals. Maximum daily dose: amlodipine 10 mg; atorvastatin 80 mg.
Terminal half-life 3-4.5 hours; prolonged in hepatic impairment (up to 15 hours) or with cimetidine.
Amlodipine: terminal half-life 30-50 h (enables once-daily dosing). Atorvastatin: terminal half-life ~14 h, but active metabolites (ortho- and para-hydroxy atorvastatin) have half-life 20-30 h; clinically, pharmacodynamic half-life (HMG-Co A reductase inhibition) is ~20-30 h.
Primarily hepatic via CYP3A4; extensive first-pass metabolism. Metabolites include desacetyldiltiazem (active, 25-50% potency).
Amlodipine: Extensively metabolized in the liver via CYP3A4 to inactive metabolites. Atorvastatin: Metabolized in the liver primarily by CYP3A4 to active ortho- and para-hydroxylated metabolites.
Renal (biliary/fecal minimal). 70-80% excreted as inactive metabolites in urine; 15% unchanged.
Amlodipine: 60% renal (metabolites), 20-25% biliary/fecal. Atorvastatin: 1% renal (unchanged), 90% biliary/fecal (≥70% as metabolites).
40-50% bound to albumin.
Amlodipine: ~93% bound to plasma proteins. Atorvastatin: ≥98% bound to plasma proteins (mainly albumin).
Vd 5-10 L/kg; reflects extensive tissue distribution (highly lipophilic).
Amlodipine: Vd ~21 L/kg (large, indicating extensive tissue distribution). Atorvastatin: Vd ~6.2 L/kg (moderately large, suggesting distribution into tissues).
IR: 30-40% (first-pass metabolism); ER (CARTIA XT): 30-40% relative to IR.
Oral: amlodipine 64-90%; atorvastatin ~14% (low due to first-pass metabolism); food reduces rate but not extent of absorption.
No specific dose adjustment is required for renal impairment. However, use with caution in patients with severe renal impairment (Cr Cl <30 m L/min) and monitor heart rate and blood pressure.
No dosage adjustment required for mild to moderate renal impairment (Cr Cl ≥30 m L/min). For severe renal impairment (Cr Cl <30 m L/min), use atorvastatin with caution; maximum atorvastatin dose is 20 mg daily. Amlodipine is not dialyzable.
Contraindicated in acute hepatic injury. For mild to moderate hepatic impairment (Child-Pugh class A/B), reduce starting dose by 50% and titrate slowly. For severe hepatic impairment (Child-Pugh class C), use is not recommended.
Contraindicated in active liver disease or unexplained persistent elevations of serum transaminases. For Child-Pugh Class A or B hepatic impairment: atorvastatin dose should be reduced; maximum atorvastatin dose is 20 mg daily. Amlodipine clearance is decreased; initial amlodipine dose should be 2.5 mg daily. No data for Child-Pugh Class C; use contraindicated.
Safety and efficacy in pediatric patients have not been established. No standard weight-based dosing guidelines are available.
Not recommended for pediatric patients. Safety and efficacy in children <10 years have not been established. For patients 10-17 years with heterozygous familial hypercholesterolemia, atorvastatin monotherapy is used; CADUET is not indicated.
In elderly patients (≥65 years), start at the lower end of the dosing range (e.g., 120–180 mg once daily) due to increased potential for bradycardia and hypotension; titrate cautiously.
Elderly patients (≥65 years) may have increased sensitivity to amlodipine; start at the lower end of dosing range (2.5 mg amlodipine component). Atorvastatin dose adjustment not required based on age alone. Monitor for hypotension and other adverse effects.
None
HMG-Co A reductase inhibitors (statins) can cause fetal harm; use in pregnant women is contraindicated. Caduet contains atorvastatin; therefore, it is contraindicated in pregnant women.
Heart failure: may worsen systolic function due to negative inotropic effects,Sick sinus syndrome or AV block: risk of bradycardia, heart block,Concomitant beta-blocker use: increased risk of bradycardia, heart failure,Hepatic impairment: reduce dose,Renal impairment: use caution,Abrupt discontinuation: may cause angina exacerbation,Sinus bradycardia: monitor heart rate
Myopathy/Rhabdomyolysis: Risk increased with higher doses, age >65, renal impairment, hypothyroidism, and concurrent use of CYP3A4 inhibitors or other drugs that cause myopathy.,Hepatic effects: Elevated liver enzymes; perform liver function tests before initiation and as clinically indicated.,Fetal toxicity: May cause fetal harm; advise females of reproductive age to use effective contraception.,Peripheral edema: More common with higher doses of amlodipine, especially in females.,Hypotension: In patients with severe aortic stenosis.
Hypersensitivity to diltiazem or any component,Sick sinus syndrome (except with functioning pacemaker),Second- or third-degree AV block (except with pacemaker),Left ventricular systolic dysfunction (ejection fraction <40%) with pulmonary congestion,Severe hypotension (systolic BP <90 mm Hg),Concurrent use of ivabradine
Active liver disease or unexplained persistent elevations of hepatic transaminases,Pregnancy,Breastfeeding (due to potential for serious adverse reactions in nursing infants),Hypersensitivity to amlodipine, atorvastatin, or any component of the formulation
Avoid grapefruit and grapefruit juice as they can increase diltiazem levels and risk of side effects. Avoid high-fat meals close to dosing as they may affect absorption. Limit alcohol intake as it may worsen hypotension or dizziness.
Avoid grapefruit and grapefruit juice as they increase atorvastatin plasma concentrations and risk of adverse effects. No significant food interactions with amlodipine.
FDA Pregnancy Category C. First trimester: No adequate studies; potential for embryotoxicity. Second and third trimesters: May cause fetal bradycardia, hypotension, hypoglycemia; risk of intrauterine growth restriction. Use only if benefit outweighs risk.
FDA Pregnancy Category X. Amlodipine: No evidence of teratogenicity in animal studies, but limited human data; atorvastatin: contraindicated in pregnancy as HMG-Co A reductase inhibitors are associated with fetal abnormalities, including skeletal and CNS defects. First trimester: Atorvastatin is contraindicated; risk of congenital anomalies. Second/third trimester: Avoid exposure; potential for fetal toxicity. Effective contraception required for women of childbearing potential.
Diltiazem is excreted in breast milk with a milk-to-plasma ratio of approximately 0.5-1.0. Limited data suggest low risk to infant, but consider monitoring for bradycardia and hypotension. Use with caution.
Excreted in human milk: Amlodipine: present in low levels (M/P ratio approximately 1.0); atorvastatin: unknown. Due to potential for serious adverse reactions in nursing infants (e.g., skeletal muscle toxicity from statins), breastfeeding is contraindicated during therapy. Alternative agents preferred.
No specific dose adjustments recommended; increased clearance in pregnancy may require dose titration based on clinical response. Monitor for hypotension and bradycardia. Use lowest effective dose.
Contraindicated during pregnancy; therefore, no dosing adjustments recommended. Discontinue therapy immediately if pregnancy is suspected or confirmed. Pharmacokinetic changes during pregnancy may alter drug metabolism, but no dose adjustments are justified due to teratogenic risk.
CARTIA XT is a sustained-release formulation of diltiazem, a calcium channel blocker. Avoid use in patients with sick sinus syndrome or second/third-degree AV block without a pacemaker. Titrate slowly to prevent hypotension. Monitor heart rate and blood pressure regularly. Use with caution in hepatic or renal impairment. Can be used for rate control in atrial fibrillation but not for conversion. Swallow capsules whole; do not crush or chew.
CADUET is a fixed-dose combination of amlodipine (a calcium channel blocker) and atorvastatin (a statin) used for hypertension and dyslipidemia. Avoid concomitant use with strong CYP3A4 inhibitors (e.g., clarithromycin, itraconazole) due to increased statin exposure and risk of myopathy. Monitor liver enzymes before and during therapy, and for muscle symptoms. Use with caution in patients with severe renal impairment. Avoid grapefruit juice as it increases atorvastatin levels.
Take this medication exactly as prescribed, usually once daily. Swallow the capsule whole; do not crush, chew, or open it.,Do not stop taking this medication suddenly without consulting your doctor, as it may worsen your condition.,Avoid drinking grapefruit juice or eating grapefruit while taking this medication.,Inform your doctor if you experience dizziness, lightheadedness, slow heartbeat, swelling of ankles/feet, or shortness of breath.,This medication may cause dizziness or drowsiness; avoid driving or operating machinery until you know how it affects you.,Keep a regular schedule for taking this medication to maintain consistent levels in your blood.
Take this medication once daily at the same time, with or without food.,Avoid grapefruit and grapefruit juice while taking this medication.,Report unexplained muscle pain, tenderness, or weakness, especially if accompanied by fever or malaise.,Notify your doctor if you become pregnant, plan to become pregnant, or are breastfeeding.,Do not stop taking this medication without consulting your doctor, even if you feel well.
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 CARTIA XT vs CADUET, answered by our medical review team.
CARTIA XT is a Calcium Channel Blocker that works by Diltiazem, a benzothiazepine calcium channel blocker, inhibits calcium ion influx across cardiac and vascular smooth muscle cells during depolarization, leading to vasodilation and reduced myocardial contractility and conduction velocity, particularly at the AV node.. CADUET is a Calcium Channel Blocker + HMG-CoA Reductase Inhibitor that works by Amlodipine: Dihydropyridine calcium channel blocker that inhibits calcium ion influx across cardiac and vascular smooth muscle cell membranes, causing vasodilation and reduced peripheral vascular resistance. Atorvastatin: HMG-Co A reductase inhibitor that competitively inhibits the conversion of HMG-Co A to mevalonate, reducing cholesterol synthesis in the liver.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between CARTIA XT and CADUET depend on the specific clinical indication. These are agents from distinct pharmacological classes and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of CARTIA XT is: Diltiazem hydrochloride extended-release capsules (CARTIA XT) are administered orally. For hypertension and angina, the typical adult dose is 180–360 mg once daily, initially 180 mg once daily, titrated to response.. The standard adult dose of CADUET is: CADUET (amlodipine/atorvastatin) is available as tablets of 2.5/10, 2.5/20, 2.5/40, 5/10, 5/20, 5/40, 5/80, 10/10, 10/20, 10/40, and 10/80 mg amlodipine/atorvastatin. Initial dose depends on current antihypertensive and lipid-lowering therapy. Usual starting dose is 5/10 mg orally once daily; titrate at intervals of 2-4 weeks based on blood pressure and LDL-C goals. Maximum daily dose: amlodipine 10 mg; atorvastatin 80 mg.. 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 CARTIA XT and CADUET 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. CARTIA XT is classified as Category C. FDA Pregnancy Category C. First trimester: No adequate studies; potential for embryotoxicity. Second and third trimesters: May cause fetal bradycardia, hypotension, hypoglycemia; r. CADUET is classified as Category C. FDA Pregnancy Category X. Amlodipine: No evidence of teratogenicity in animal studies, but limited human data; atorvastatin: contraindicated in pregnancy as HMG-CoA reductase inhib. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.