Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
CARDIZEM SR 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 inhibits calcium ion influx across cardiac and vascular smooth muscle cell membranes during depolarization, leading to negative inotropic, chronotropic, and dromotropic effects, and vasodilation.
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,Angina pectoris due to coronary artery spasm (Prinzmetal's variant angina),Chronic stable angina (classic effort-associated 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
Oral: Initial dose 60-120 mg twice daily; titrate to maximum 360 mg/day divided into two doses.
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.
3.0-4.5 hours for diltiazem; metabolites (e.g., desacetyldiltiazem) up to 10 hours. Clinical context: dosing interval adjustment in hepatic impairment.
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; undergoes extensive first-pass metabolism.
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: ~60-70% (including active metabolites); fecal: ~30-40%.
Amlodipine: 60% renal (metabolites), 20-25% biliary/fecal. Atorvastatin: 1% renal (unchanged), 90% biliary/fecal (≥70% as metabolites).
Approximately 70-80%, primarily to albumin and alpha-1-acid glycoprotein.
Amlodipine: ~93% bound to plasma proteins. Atorvastatin: ≥98% bound to plasma proteins (mainly albumin).
3.1-5.1 L/kg; large Vd indicates extensive tissue distribution (e.g., myocardium, vascular smooth muscle).
Amlodipine: Vd ~21 L/kg (large, indicating extensive tissue distribution). Atorvastatin: Vd ~6.2 L/kg (moderately large, suggesting distribution into tissues).
Oral (sustained-release): approximately 40-50% due to first-pass metabolism; variable among formulations.
Oral: amlodipine 64-90%; atorvastatin ~14% (low due to first-pass metabolism); food reduces rate but not extent of absorption.
For GFR < 10 m L/min: Use with caution and reduce dose by 25-50%; consider extended dosing interval.
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 B: Reduce dose by 50%; Child-Pugh Class C: Use 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 not established; no specific weight-based dosing guidelines 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.
Initial dose 60 mg twice daily; titrate slowly due to increased risk of bradycardia and hypotension.
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.
Cardiac conduction abnormalities: bradycardia, AV block, sick sinus syndrome,Heart failure: use with caution in patients with compromised ventricular function,Hypotension,Hepatic impairment,Concomitant use with beta-blockers may increase risk of bradycardia and AV block,Abrupt discontinuation may exacerbate angina
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 patients with a functioning artificial ventricular pacemaker),Second- or third-degree AV block (except in patients with a functioning artificial ventricular pacemaker),Hypotension (systolic blood pressure < 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 and grapefruit juice increase diltiazem levels by inhibiting CYP3A4 metabolism; avoid concurrent use. No other significant food restrictions. Alcohol may enhance hypotensive effects and increase risk of 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. No adequate studies in pregnant women. In animal studies, diltiazem has been shown to cause embryofetal toxicity (skeletal abnormalities, reduced fetal weight) at doses 5-10 times the maximum recommended human dose. Risk to fetus cannot be ruled out; use only if potential benefit justifies potential 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 into human breast milk at low concentrations. Estimated infant dose is <1% of maternal weight-adjusted dose. M/P ratio not established. Although risk to nursing infant is likely low, caution is advised. Monitor infant for bradycardia, hypotension, and feeding difficulties.
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 adjustment guidelines for pregnancy; however, pharmacokinetic changes in pregnancy (increased volume of distribution, altered hepatic metabolism) may require dose titration based on clinical response and tolerability. Start at lowest effective dose and monitor closely.
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.
Cardizem SR is a sustained-release calcium channel blocker indicated for hypertension and angina. Onset: 2-3 hours, duration: 12-24 hours. Avoid concurrent use with beta-blockers due to risk of bradycardia and heart block. Contraindicated in sick sinus syndrome (unless pacemaker), second- or third-degree AV block, hypotension (SBP <90 mm Hg), and acute MI with pulmonary congestion. Monitor liver function and renal function; dose adjustment needed in hepatic impairment. Use caution in patients with decreased left ventricular function (ejection fraction <40%). Do not crush or chew capsules; swallow whole.
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, with or without food, at the same time each day.,Swallow the capsule whole; do not crush, chew, or open it.,Avoid grapefruit and grapefruit juice while on this medication; they can increase the drug's effect and risk of side effects.,Do not stop taking this medication suddenly; abrupt discontinuation may worsen chest pain or increase blood pressure.,Contact your healthcare provider if you experience slow heartbeat, fainting, dizziness, shortness of breath, or swelling of the legs/ankles.,Limit alcohol consumption as it may increase the risk of side effects such as dizziness or fainting.,Inform your doctor if you are pregnant, planning to become pregnant, or breastfeeding.,Keep all appointments to check your blood pressure and heart rhythm.
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 SR vs CADUET, answered by our medical review team.
CARDIZEM SR is a Calcium Channel Blocker that works by Diltiazem inhibits calcium ion influx across cardiac and vascular smooth muscle cell membranes during depolarization, leading to negative inotropic, chronotropic, and dromotropic effects, and vasodilation.. 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 SR 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 SR is: Oral: Initial dose 60-120 mg twice daily; titrate to maximum 360 mg/day divided into two doses.. 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 SR 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 SR is classified as Category C. FDA Pregnancy Category C. No adequate studies in pregnant women. In animal studies, diltiazem has been shown to cause embryofetal toxicity (skeletal abnormalities, reduced fetal we. 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.