Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
TIAZAC 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 cell membranes, resulting in coronary vasodilation, peripheral vasodilation, decreased myocardial contractility, and decreased AV nodal 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 pectoris,Atrial fibrillation or atrial flutter (rate control),Paroxysmal supraventricular tachycardia (PSVT)
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: 120-360 mg once daily; maximum 540 mg daily.
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 is 5-7 hours for immediate-release; for TIAZAC (extended-release), effective half-life is approximately 6-9 hours due to prolonged absorption
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 isoenzyme; extensive first-pass metabolism; metabolites include N-desmethyl diltiazem (active) and others.
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, 60% as inactive metabolites); Fecal (30%); Biliary (minor)
Amlodipine: 60% renal (metabolites), 20-25% biliary/fecal. Atorvastatin: 1% renal (unchanged), 90% biliary/fecal (≥70% as metabolites).
70-80% bound to plasma proteins (albumin)
Amlodipine: ~93% bound to plasma proteins. Atorvastatin: ≥98% bound to plasma proteins (mainly albumin).
Approximately 1.7 L/kg; suggests extensive tissue distribution
Amlodipine: Vd ~21 L/kg (large, indicating extensive tissue distribution). Atorvastatin: Vd ~6.2 L/kg (moderately large, suggesting distribution into tissues).
Approximately 40% for oral immediate-release; extended-release formulation has comparable bioavailability with reduced peak-to-trough fluctuations
Oral: amlodipine 64-90%; atorvastatin ~14% (low due to first-pass metabolism); food reduces rate but not extent of absorption.
No specific adjustment required; use with 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: no adjustment; Child-Pugh Class B: reduce total dose by 50%; Child-Pugh Class C: reduce total dose by 60-70%.
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 established; use in children <18 years is not recommended.
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 daily); titrate slowly due to increased sensitivity and potential for 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.
Bradycardia and heart block (risk increased with beta-blockers or digoxin),Heart failure with reduced ejection fraction (may worsen in acute MI or pulmonary congestion),Hypotension,Increased risk of gastrointestinal bleeding in elderly,Hepatic impairment (dose adjustment may be required),Abrupt withdrawal may exacerbate angina or cause rebound hypertension,Concurrent use with CYP3A4 inhibitors (e.g., clarithromycin, itraconazole) increases diltiazem levels
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 (unless paced),Second- or third-degree AV block (unless paced),Hypotension (systolic < 90 mm Hg),Cardiogenic shock,Atrial fibrillation/flutter with accessory bypass tract (e.g., Wolff-Parkinson-White syndrome, Lown-Ganong-Levine syndrome),Acute myocardial infarction with pulmonary congestion,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
Avoid grapefruit juice and grapefruit products due to CYP3A4 inhibition, which can increase diltiazem levels. Limit sodium intake as part of hypertension management. No significant interaction with other foods.
Avoid grapefruit and grapefruit juice as they increase atorvastatin plasma concentrations and risk of adverse effects. No significant food interactions with amlodipine.
TIAZAC (diltiazem) is classified as FDA Pregnancy Category C. First trimester: Limited human data; animal studies have shown embryotoxic and teratogenic effects at high doses. Second and third trimesters: No well-controlled studies; risk of fetal bradycardia, hypotension, and hypocalcemia due to calcium channel blockade. 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 into human breast milk at low concentrations. The milk-to-plasma ratio is approximately 0.4 to 0.8. Relative infant dose is estimated to be <1% of maternal weight-adjusted dose; considered compatible with breastfeeding. Monitor infant for potential adverse effects such as bradycardia, hypotension, or sedation.
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 may alter the pharmacokinetics of diltiazem due to increased plasma volume, renal clearance, and hepatic metabolism. Dose adjustments may be necessary; titrate to clinical effect. No specific dosing guidelines; use the lowest effective dose and monitor blood pressure and heart rate 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.
TIAZAC (diltiazem extended-release) is a nondihydropyridine calcium channel blocker used for hypertension and stable angina. Avoid use in patients with sick sinus syndrome or second/third-degree AV block without a pacemaker. It is a substrate of CYP3A4; monitor for interactions with strong inhibitors (e.g., ketoconazole) or inducers (e.g., rifampin). In hepatic impairment, start at lowest dose. Use with beta-blockers increases risk of bradycardia and heart failure. May cause gingival hyperplasia; stress good oral hygiene.
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 TIAZAC exactly as prescribed, usually once daily. Swallow the capsule whole; do not crush, chew, or open.,Do not stop taking this medication abruptly, as it may worsen chest pain or blood pressure.,Avoid drinking grapefruit juice or eating grapefruit while on this drug, as it can increase side effects.,Common side effects include dizziness, headache, swelling in the ankles/feet, and constipation. Contact your doctor if you experience very slow heartbeat, fainting, or shortness of breath.,Inform your doctor about all other medications, especially beta-blockers, digoxin, or other blood pressure drugs.
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 TIAZAC vs CADUET, answered by our medical review team.
TIAZAC is a Calcium Channel Blocker that works by Diltiazem, a benzothiazepine calcium channel blocker, inhibits calcium ion influx across cardiac and vascular smooth muscle cell membranes, resulting in coronary vasodilation, peripheral vasodilation, decreased myocardial contractility, and decreased AV nodal 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 TIAZAC 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 TIAZAC is: Oral: 120-360 mg once daily; maximum 540 mg daily.. 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 TIAZAC 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. TIAZAC is classified as Category C. TIAZAC (diltiazem) is classified as FDA Pregnancy Category C. First trimester: Limited human data; animal studies have shown embryotoxic and teratogenic effects at high doses. Seco. 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.