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Registry Hub
Peer-Reviewed Evidence
HomeDrug RegistryCompareCADUET vs ACTAHIST
Comparative Pharmacology

CADUET vs ACTAHIST Comparison

Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.

Clinical EssentialsPharmacokineticsSpecial PopulationsSafety & MonitoringPregnancy & LactationClinical Insights
Differential Analysis

CADUET vs ACTAHIST

Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.

View CADUET Monograph View ACTAHIST Monograph
CADUET
Calcium Channel Blocker + HMG-CoA Reductase Inhibitor
Category C
ACTAHIST
Antihistamine
Category C
TL;DR — Key Differences
  • Drug class: CADUET is a Calcium Channel Blocker + HMG-CoA Reductase Inhibitor; ACTAHIST is a Antihistamine.
  • Half-life: CADUET has a half-life of 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.; ACTAHIST has 6.9 ± 1.7 hours in adults; prolonged to 12-18 hours in elderly or patients with hepatic impairment, requiring dosing interval adjustment..
  • No direct drug-drug interaction has been documented between CADUET and ACTAHIST.
  • Pregnancy: CADUET is rated Category C; ACTAHIST is rated Category C.

Last clinically reviewed: July 2026 · OpiCalc Medical Review Team

Clinical Essentials

CADUET
ACTAHIST
Mechanism of Action
CADUET

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.

ACTAHIST

Antihistamine; binds to histamine H1 receptors, blocking the effects of histamine; also exhibits anticholinergic and mild sedative properties.

Indications
CADUET

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

ACTAHIST

Symptomatic relief of allergic rhinitis,Urticaria,Off-label: motion sickness,Off-label: insomnia

Standard Dosing
CADUET

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.

ACTAHIST

1.34 mg (one capsule) orally twice daily.

Direct Interaction
CADUET
No Direct Interaction
ACTAHIST
No Direct Interaction

Pharmacokinetics

CADUET
ACTAHIST
Half-Life
CADUET

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.

ACTAHIST

6.9 ± 1.7 hours in adults; prolonged to 12-18 hours in elderly or patients with hepatic impairment, requiring dosing interval adjustment.

Metabolism
CADUET

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.

ACTAHIST

Hepatic metabolism via CYP450 enzymes (primarily CYP3A4 and CYP2D6); major metabolite is inactive.

Excretion
CADUET

Amlodipine: 60% renal (metabolites), 20-25% biliary/fecal. Atorvastatin: 1% renal (unchanged), 90% biliary/fecal (≥70% as metabolites).

ACTAHIST

Primarily renal (approximately 85% as unchanged drug and metabolites) and fecal (15%) via biliary elimination.

Protein Binding
CADUET

Amlodipine: ~93% bound to plasma proteins. Atorvastatin: ≥98% bound to plasma proteins (mainly albumin).

ACTAHIST

92% bound to albumin.

VD (L/kg)
CADUET

Amlodipine: Vd ~21 L/kg (large, indicating extensive tissue distribution). Atorvastatin: Vd ~6.2 L/kg (moderately large, suggesting distribution into tissues).

ACTAHIST

0.9 ± 0.3 L/kg, indicating extensive extravascular distribution.

Bioavailability
CADUET

Oral: amlodipine 64-90%; atorvastatin ~14% (low due to first-pass metabolism); food reduces rate but not extent of absorption.

ACTAHIST

Oral: 68% ± 12% due to first-pass metabolism.

Special Populations

CADUET
ACTAHIST
Renal Adjustments
CADUET

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.

ACTAHIST

No dose adjustment required for mild to moderate renal impairment. Safety not established for severe impairment (GFR <30 m L/min).

Hepatic Adjustments
CADUET

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.

ACTAHIST

No dose adjustment required for mild to moderate hepatic impairment (Child-Pugh A or B). Not recommended for severe hepatic impairment (Child-Pugh C).

Pediatric Dosing
CADUET

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.

ACTAHIST

Not indicated for pediatric patients under 12 years of age. Safety and efficacy not established.

Geriatric Dosing
CADUET

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.

ACTAHIST

No specific dose adjustment recommended; monitor for increased anticholinergic effects and cognitive impairment.

Safety & Monitoring

CADUET
ACTAHIST
Black Box Warnings
CADUET
FDA Black Box Warning

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.

ACTAHIST
FDA Black Box Warning

None.

Warnings/Precautions
CADUET

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.

ACTAHIST

May cause drowsiness; caution when driving or operating machinery. Avoid alcohol. Use with caution in patients with narrow-angle glaucoma, prostatic hyperplasia, or urinary retention. Geriatric patients more sensitive to anticholinergic effects. Pediatric patients <6 years: not recommended.

Contraindications
CADUET

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

ACTAHIST

Hypersensitivity to any component. Newborns or premature infants. Breastfeeding (contraindicated due to risk of adverse effects in infants). Concomitant use with MAOIs.

Adverse Reactions
CADUET
Data Pending
ACTAHIST
Data Pending
Food Interactions
CADUET

Avoid grapefruit and grapefruit juice as they increase atorvastatin plasma concentrations and risk of adverse effects. No significant food interactions with amlodipine.

ACTAHIST

Avoid high-tyramine foods (aged cheese, cured meats, fermented products) if taking MAOIs. Grapefruit juice may increase phenylephrine absorption; limit intake.

Pregnancy & Lactation

CADUET
ACTAHIST
Teratogenic Risk
CADUET

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.

ACTAHIST

ACTAHIST (brompheniramine/phenylephrine) pregnancy category C. Inadequate human data; animal studies show no malformations at therapeutic doses. First trimester: theoretical risk from vasoconstrictive effects (phenylephrine) possibly reducing uterine blood flow; avoid if possible. Second/third trimester: phenylephrine may cause fetal hypoxia via placental vasoconstriction; use only if benefit outweighs risk. No known structural teratogenicity.

Lactation Summary
CADUET

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.

ACTAHIST

Brompheniramine is excreted in breast milk in small amounts; M/P ratio not established. Phenylephrine has minimal excretion. Due to anticholinergic effects, may reduce milk production or cause sedation in infants. Use caution; prefer non-sedating alternatives if possible.

Pregnancy Dosing
CADUET

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.

ACTAHIST

No specific pharmacokinetic studies. Increased plasma volume and renal clearance in pregnancy may reduce drug levels, but efficacy threshold remains. No dose adjustment recommended; use the lowest effective dose for shortest duration due to potential risks.

Maternal Safety Status
CADUET
Category C
ACTAHIST
Category C

Clinical Insights

CADUET
ACTAHIST
Clinical Pearls
CADUET

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.

ACTAHIST

Actahist is a combination antihistamine-decongestant (chlorpheniramine/phenylephrine). Avoid in patients with hypertension, severe coronary artery disease, or MAOI use. Monitor for sedation and urinary retention, especially in elderly males with BPH.

Patient Counseling
CADUET

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.

ACTAHIST

Take with food or milk to reduce stomach upset.,Avoid alcohol and CNS depressants as they can increase drowsiness.,Do not drive or operate machinery until you know how this medication affects you.,Contact your doctor if you experience chest pain, rapid heartbeat, or difficulty urinating.

Safety Verification

Known Interactions

CADUET Risks

No interactions on record

ACTAHIST Risks

No interactions on record

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Clinical Q&A

Frequently Asked Questions

Common clinical questions about CADUET vs ACTAHIST, answered by our medical review team.

1. What is the main difference between CADUET and ACTAHIST?

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.. ACTAHIST is a Antihistamine that works by Antihistamine; binds to histamine H1 receptors, blocking the effects of histamine; also exhibits anticholinergic and mild sedative properties.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.

2. Which is stronger: CADUET or ACTAHIST?

Potency comparisons between CADUET and ACTAHIST 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.

3. What is the standard dosing for CADUET vs ACTAHIST?

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.. The standard adult dose of ACTAHIST is: 1.34 mg (one capsule) orally twice daily.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.

4. Can you take CADUET and ACTAHIST together?

No direct drug-drug interaction has been formally documented between CADUET and ACTAHIST 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.

5. Are CADUET and ACTAHIST safe during pregnancy?

The maternal-fetal safety profiles differ. 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. ACTAHIST is classified as Category C. ACTAHIST (brompheniramine/phenylephrine) pregnancy category C. Inadequate human data; animal studies show no malformations at therapeutic doses. First trimester: theoretical risk f. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.