Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
AZOR vs ALDOCLOR-250
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Amlodipine is a dihydropyridine calcium channel blocker that inhibits calcium ion influx across cardiac and vascular smooth muscle cells, causing vasodilation and reduced peripheral vascular resistance. Olmesartan is an angiotensin II receptor blocker (ARB) that selectively blocks AT1 receptors, inhibiting vasoconstriction and aldosterone secretion.
Aldoclor-250 is a combination of methyldopa and chlorothiazide. Methyldopa is a centrally acting alpha-2 adrenergic agonist that reduces sympathetic outflow from the brain, decreasing peripheral vascular resistance and blood pressure. Chlorothiazide is a thiazide diuretic that inhibits sodium and chloride reabsorption in the distal convoluted tubule, increasing urinary output and reducing plasma volume.
Treatment of hypertension, alone or with other antihypertensive agents
Hypertension (first-line or adjunctive therapy),Off-label: Management of hypertensive crisis (as part of combination therapy)
AZOR is a combination of amlodipine and olmesartan. Typical adult dose: one tablet orally once daily. Available strengths: amlodipine/olmesartan 5mg/20mg, 5mg/40mg, 10mg/20mg, 10mg/40mg. Dose can be titrated based on blood pressure response.
250 mg orally twice daily
Amlodipine: 30-50 h (terminal); supports once-daily dosing. Olmesartan: 10-15 h (terminal); once-daily dosing effective
1.5-3 hours; prolonged in renal impairment (up to 20 hours with Cr Cl <10 m L/min).
Amlodipine is extensively metabolized in the liver via CYP3A4 to inactive metabolites. Olmesartan is metabolized by the liver to a minor extent; it undergoes glucuronidation and some oxidation by CYP2C9.
Methyldopa: Primarily hepatic metabolism via catecholamine pathways; conjugated to sulfate and other metabolites. Chlorothiazide: Not extensively metabolized; excreted unchanged in urine.
Renal: 90% (amlodipine: 60% as metabolites, 10% as parent; olmesartan: 35-50% as parent via urine, rest in feces via bile). Fecal: 10%
Renal (70-80% unchanged), biliary/fecal (15-25% as metabolites); total clearance ~250 m L/min.
Amlodipine: ~93% bound to plasma proteins. Olmesartan: >99% bound to albumin
25-40% bound primarily to albumin and alpha-1-acid glycoprotein.
Amlodipine: 21 L/kg (large, extensive tissue distribution). Olmesartan: 17-30 L (approximate, Vd not typically reported per kg); distribution into tissues
0.6-1.0 L/kg; indicates distribution into total body water and some tissue binding.
Oral: amlodipine 64-90% (high, first-pass ~10%); olmesartan 26% (oral, complete absorption reduced by first-pass ester hydrolysis)
70-90% (oral); 100% (IV).
No dose adjustment is required for mild to moderate renal impairment (Cr Cl ≥30 m L/min). For severe renal impairment (Cr Cl <30 m L/min), use with caution; maximum dose of olmesartan is 20 mg once daily. Monitor serum potassium and creatinine.
Cr Cl >50 m L/min: no adjustment; Cr Cl 10-50 m L/min: 250 mg once daily; Cr Cl <10 m L/min: 250 mg every 48 hours
No dose adjustment for mild hepatic impairment (Child-Pugh A). For moderate to severe hepatic impairment (Child-Pugh B or C), amlodipine half-life is prolonged; initiate with amlodipine 2.5 mg and olmesartan 10 mg, and titrate slowly. Use caution; contraindicated in severe hepatic impairment with cholestasis? Not specifically contraindicated but not recommended.
Child-Pugh A: no adjustment; Child-Pugh B: use with caution, reduce dose by 50%; Child-Pugh C: avoid use
Safety and efficacy in pediatric patients <18 years have not been established. Not recommended for use in children.
Not recommended for use in pediatric patients due to lack of safety and efficacy data
In elderly patients (≥65 years), start with the lowest available dose (amlodipine/olmesartan 5/20 mg daily) and titrate slowly due to increased sensitivity and potential for hypotension. Monitor renal function and electrolytes closely in geriatric patients.
Start at lower end of dosing range; monitor renal function closely; adjust dose based on Cr Cl
None
None explicitly listed. However, methyldopa carries a warning for hepatotoxicity and hemolytic anemia; chlorothiazide carries a warning for electrolyte disturbances and hypersensitivity reactions.
Fetal toxicity (detectable in second and third trimesters): drugs acting on the renin-angiotensin system can cause oligohydramnios, fetal renal dysfunction, and death,Avoid concomitant use with aliskiren in patients with diabetes,Hypotension in volume/depleted patients,Increased angina or myocardial infarction with calcium channel blockers, particularly with severe obstructive coronary artery disease,Peripheral edema is dose-dependent and more common with amlodipine,Hepatic impairment: lower starting dose,Renal artery stenosis,Electrolyte imbalances
Hepatotoxicity (methyldopa), hemolytic anemia, positive direct Coombs test, sedation, depression, bradycardia, orthostatic hypotension, electrolyte imbalance (hypokalemia, hyponatremia, hypomagnesemia), hyperuricemia, hyperglycemia, photosensitivity, lupus-like syndrome, and hypersensitivity reactions.
Hypersensitivity to any component,Do not use with aliskiren in patients with diabetes
Active hepatic disease, history of previous methyldopa-induced liver dysfunction, hemolytic anemia associated with methyldopa, anuria, hypersensitivity to methyldopa, chlorothiazide, or sulfonamide-derived drugs, severe renal impairment (Cr Cl <30 m L/min), and concomitant therapy with MAO inhibitors.
Avoid grapefruit and grapefruit juice due to CYP3A4 inhibition increasing amlodipine levels. No other significant food interactions.
Avoid high-potassium foods (bananas, oranges, spinach) unless specifically advised; chlorothiazide may cause potassium loss, but methyldopa can cause potassium retention. Avoid excessive alcohol intake as it may potentiate hypotension. Take with food to reduce gastrointestinal upset. May decrease glucose tolerance; monitor in diabetic patients.
Pregnancy Category D. First trimester: Potential for fetal toxicity (oligohydramnios, fetal/neonatal renal dysfunction, skull hypoplasia) due to olmesartan action on renin-angiotensin system; avoid use. Second trimester: Continued risk of fetal renal impairment and oligohydramnios. Third trimester: High risk of fetal/neonatal renal failure, hypotension, hyperkalemia, and skull ossification defects; contraindicated.
FDA Pregnancy Category D. First trimester: Associated with cardiovascular defects (e.g., VSD), neural tube defects, and oral clefts. Second and third trimesters: Fetal nephrotoxicity (oligohydramnios, renal failure), premature closure of ductus arteriosus, pulmonary hypertension, and intracranial hemorrhage. Avoid in third trimester.
No human data on olmesartan or amlodipine excretion in breast milk. Amlodipine transfers into human milk with M/P ratio approximately 0.5-1.5; risk to infant unknown. Due to potential for adverse effects (hypotension, renal impairment), use is not recommended. Alternative antihypertensives with more safety data should be considered.
Chlorothiazide is excreted in breast milk; M/P ratio unknown. Can suppress lactation. Use only if maternal benefit outweighs potential infant risks (e.g., electrolyte disturbances, thrombocytopenia).
Not applicable; use is contraindicated in pregnancy. No dose adjustment can mitigate fetal risk; alternative agents (e.g., labetalol, nifedipine) are preferred. If inadvertently used, discontinue as soon as pregnancy is detected.
Increased volume of distribution and GFR in pregnancy may necessitate higher doses for equivalent effect. Start at lowest effective dose; titrate based on BP response. Monitor for hypokalemia and metabolic alkalosis.
AZOR is a fixed-dose combination of amlodipine (calcium channel blocker) and olmesartan (angiotensin II receptor blocker). Monitor serum potassium and creatinine, especially in renal impairment or concomitant ACE inhibitor use. Avoid in pregnancy (use effective contraception). May cause dizziness or peripheral edema, often dose-related.
Aldoclor-250 is a combination of methyldopa (250mg) and chlorothiazide. Methyldopa can cause a positive direct Coombs test (10-20% of patients) which may interfere with blood cross-matching; obtain a hematocrit and Coombs test before therapy and at 6 and 12 months. Chlorothiazide may cause hypokalemia; monitor potassium and consider potassium supplementation. Onset of methyldopa is 3-6 hours; delay full effect for 48-72 hours. Avoid use in patients with active liver disease or history of previous methyldopa-induced liver dysfunction.
Take exactly as prescribed, usually once daily, with or without food.,Avoid grapefruit or grapefruit juice as it can increase amlodipine levels.,Notify your doctor if you become pregnant or plan to become pregnant.,Do not stop taking suddenly; consult your doctor before discontinuing.,Report lightheadedness, fainting, or significant swelling in your ankles or feet.,Use caution when driving or operating machinery until you know how this medication affects you.
Take exactly as prescribed; do not skip doses or stop suddenly.,May cause drowsiness or dizziness; avoid driving or operating machinery until you know how it affects you.,Rise slowly from sitting or lying to prevent lightheadedness.,Report any unexplained fever, jaundice, or dark urine immediately.,Use sun protection; this drug may increase sensitivity to sunlight.,Do not use potassium supplements or salt substitutes without consulting your doctor.,If you miss a dose, take it as soon as you remember unless it's near the next dose; do not double.
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 AZOR vs ALDOCLOR-250, answered by our medical review team.
AZOR is a Antihypertensive Combination that works by Amlodipine is a dihydropyridine calcium channel blocker that inhibits calcium ion influx across cardiac and vascular smooth muscle cells, causing vasodilation and reduced peripheral vascular resistance. Olmesartan is an angiotensin II receptor blocker (ARB) that selectively blocks AT1 receptors, inhibiting vasoconstriction and aldosterone secretion.. ALDOCLOR-250 is a Antihypertensive Combination (Central Alpha Agonist and Thiazide Diuretic) that works by Aldoclor-250 is a combination of methyldopa and chlorothiazide. Methyldopa is a centrally acting alpha-2 adrenergic agonist that reduces sympathetic outflow from the brain, decreasing peripheral vascular resistance and blood pressure. Chlorothiazide is a thiazide diuretic that inhibits sodium and chloride reabsorption in the distal convoluted tubule, increasing urinary output and reducing plasma volume.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between AZOR and ALDOCLOR-250 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 AZOR is: AZOR is a combination of amlodipine and olmesartan. Typical adult dose: one tablet orally once daily. Available strengths: amlodipine/olmesartan 5mg/20mg, 5mg/40mg, 10mg/20mg, 10mg/40mg. Dose can be titrated based on blood pressure response.. The standard adult dose of ALDOCLOR-250 is: 250 mg orally twice daily. 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 AZOR and ALDOCLOR-250 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. AZOR is classified as Category C. Pregnancy Category D. First trimester: Potential for fetal toxicity (oligohydramnios, fetal/neonatal renal dysfunction, skull hypoplasia) due to olmesartan action on renin-angioten. ALDOCLOR-250 is classified as Category C. FDA Pregnancy Category D. First trimester: Associated with cardiovascular defects (e.g., VSD), neural tube defects, and oral clefts. Second and third trimesters: Fetal nephrotoxici. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.