Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
CARDIZEM CD 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 is a calcium channel blocker that inhibits calcium ion influx across cardiac and vascular smooth muscle cell membranes, resulting in dilation of coronary arteries and peripheral arterioles, and decreased myocardial contractility and conduction velocity.
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.
Hypertension,Chronic stable angina,Variant angina
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
Hypertension: 180-360 mg once daily orally. Angina: 120-360 mg once daily orally. Maximum dose: 480 mg/day.
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 elimination half-life: 6-8 hours (single dose), prolonged to 10-15 hours with multiple dosing or in elderly/hepatic impairment. Clinical context: Therapeutic steady-state achieved in 2-4 days.
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.
Hepatic via CYP3A4; also undergoes deacetylation; substrate of P-glycoprotein.
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: ~2-4% (unchanged), Hepatic metabolism to multiple metabolites; ~65% renal (metabolites), ~35% fecal/biliary. Total clearance: 5-7 m L/kg/min.
Amlodipine: 60% renal (metabolites), 20-25% biliary/fecal. Atorvastatin: 1% renal (unchanged), 90% biliary/fecal (≥70% as metabolites).
70-80% bound primarily to albumin (70%), also alpha-1 acid glycoprotein (10%). Binding saturable at high concentrations.
Amlodipine: ~93% bound to plasma proteins. Atorvastatin: ≥98% bound to plasma proteins (mainly albumin).
Approximately 5.3 L/kg. Meaning: Extensive tissue distribution (3-5 L/kg); reflects high lipophilicity and wide distribution beyond plasma.
Amlodipine: Vd ~21 L/kg (large, indicating extensive tissue distribution). Atorvastatin: Vd ~6.2 L/kg (moderately large, suggesting distribution into tissues).
Extended-release (Cardizem CD): ~40% (range 35-45%) due to extensive first-pass metabolism. Immediate-release: ~40-50%. IV: 100%.
Oral: amlodipine 64-90%; atorvastatin ~14% (low due to first-pass metabolism); food reduces rate but not extent of absorption.
No specific GFR-based adjustment required, but use caution in severe renal impairment (Cr Cl <30 m L/min).
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.
Child-Pugh Class A: start with 120 mg once daily. Child-Pugh Class B: start with 120 mg once daily, titrate cautiously. Child-Pugh Class C: contraindicated.
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.
Not approved for pediatric use; safety and efficacy not established.
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.
Start at lower end of dosing range (120 mg once daily) due to increased risk of hypotension and bradycardia; titrate slowly.
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.
May cause hypotension,Risk of heart failure exacerbation in patients with impaired ventricular function,May slow AV conduction, leading to bradycardia or AV block,Hepatic and renal impairment caution,May exacerbate symptoms in patients with hypertrophic cardiomyopathy
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.
Sick sinus syndrome (except in presence of functioning ventricular pacemaker),Second- or third-degree AV block (except in presence of functioning ventricular pacemaker),Hypotension (systolic < 90 mm Hg),Acute myocardial infarction with pulmonary congestion,Known hypersensitivity to diltiazem
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
Grapefruit juice may increase diltiazem serum concentrations; avoid concurrent ingestion. Alcohol may enhance hypotensive effects. No significant food restrictions otherwise.
Avoid grapefruit and grapefruit juice as they increase atorvastatin plasma concentrations and risk of adverse effects. No significant food interactions with amlodipine.
Diltiazem, the active ingredient in Cardizem CD, is classified as Pregnancy Category C. Animal studies have demonstrated embryotoxicity and teratogenicity (skeletal abnormalities) at doses 5-10 times the maximum recommended human dose. There are no adequate and well-controlled studies in pregnant women. In humans, exposure during the first trimester may be associated with a small increased risk of congenital anomalies, particularly cardiac defects, though data are limited. During the second and third trimesters, use may be associated with potential risks of fetal growth restriction and preterm labor due to maternal hypotension and decreased uteroplacental perfusion. The drug should only be used if the potential benefit justifies the potential risk to the fetus.
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 into human milk at low concentrations; the milk-to-plasma (M/P) ratio is approximately 0.8. Limited data suggest that the estimated infant daily dose is less than 1% of the maternal weight-adjusted dose. While adverse effects in breastfed infants have not been reported, caution is advised due to potential for cardiovascular effects. The manufacturer recommends discontinuing breastfeeding or the drug, considering the importance of the drug to the mother.
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.
Pregnancy-induced increases in plasma volume and hepatic metabolism may reduce diltiazem concentrations, potentially requiring dose adjustments. However, specific pharmacokinetic studies in pregnant women are lacking. Clinical monitoring of therapeutic effect (e.g., blood pressure control) should guide dosing; gradual titration is recommended, and doses may need to be increased based on response. Avoid abrupt discontinuation.
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.
Diltiazem (Cardizem CD) is a nondihydropyridine calcium channel blocker; use with caution in patients with systolic heart failure (HFr EF) due to negative inotropic effects. Avoid concurrent use with beta-blockers due to risk of bradycardia and heart block. May increase dugoxin levels; monitor digoxin levels. Contraindicated in sick sinus syndrome or second/third-degree AV block without pacemaker. Also inhibits CYP3A4; monitor for interactions with statins (e.g., simvastatin dose limit 10 mg).
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 capsule whole; do not crush or chew. May be taken without regard to meals.,Do not stop abruptly; gradual taper advised to avoid rebound hypertension or ischemia.,Report symptoms of bradycardia (dizziness, fainting) or heart failure (swelling, shortness of breath).,Avoid grapefruit juice as it may increase drug levels and risk of side effects.,Use sunscreen and protective clothing due to possible photosensitivity.
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 CARDIZEM CD vs CADUET, answered by our medical review team.
CARDIZEM CD 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 cell membranes, resulting in dilation of coronary arteries and peripheral arterioles, and decreased myocardial contractility and conduction velocity.. 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 CARDIZEM CD 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 CARDIZEM CD is: Hypertension: 180-360 mg once daily orally. Angina: 120-360 mg once daily orally. Maximum dose: 480 mg/day.. 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 CARDIZEM CD 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. CARDIZEM CD is classified as Category C. Diltiazem, the active ingredient in Cardizem CD, is classified as Pregnancy Category C. Animal studies have demonstrated embryotoxicity and teratogenicity (skeletal abnormalities) . 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.