Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
AZOR vs ALDORIL D50
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.
Aldoril D50 is a combination of methyldopa and hydrochlorothiazide. Methyldopa is a centrally-acting alpha-2 adrenergic agonist that reduces sympathetic outflow from the brainstem, decreasing peripheral vascular resistance and blood pressure. Hydrochlorothiazide is a thiazide diuretic that inhibits sodium reabsorption in the distal convoluted tubule, reducing plasma volume and further lowering blood pressure.
Treatment of hypertension, alone or with other antihypertensive agents
Hypertension (first-line or second-line therapy),Hypertensive urgency (off-label)
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.
1 tablet (hydrochlorothiazide 25 mg + methyldopa 250 mg) orally twice daily; maximum dose: 2 tablets (50 mg + 500 mg) twice daily.
Amlodipine: 30-50 h (terminal); supports once-daily dosing. Olmesartan: 10-15 h (terminal); once-daily dosing effective
3–6 hours (terminal elimination half-life); clinical context: requires twice-daily dosing for sustained blood pressure control; prolonged in renal impairment.
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 is extensively metabolized in the liver via conjugation and O-methylation, with involvement of catechol-O-methyltransferase (COMT). Hydrochlorothiazide is not extensively metabolized; it is eliminated largely unchanged by the kidneys.
Renal: 90% (amlodipine: 60% as metabolites, 10% as parent; olmesartan: 35-50% as parent via urine, rest in feces via bile). Fecal: 10%
Renal: 50% as unchanged drug and 20% as metabolites; biliary/fecal: ~25% (as metabolites); total renal clearance accounts for ~70% of elimination.
Amlodipine: ~93% bound to plasma proteins. Olmesartan: >99% bound to albumin
~20% bound to albumin; minimal binding to other plasma proteins.
Amlodipine: 21 L/kg (large, extensive tissue distribution). Olmesartan: 17-30 L (approximate, Vd not typically reported per kg); distribution into tissues
0.2–0.3 L/kg (moderately low Vd, indicating limited extravascular distribution and predominantly plasma water distribution).
Oral: amlodipine 64-90% (high, first-pass ~10%); olmesartan 26% (oral, complete absorption reduced by first-pass ester hydrolysis)
Oral: 30–40% (due to extensive first-pass metabolism); IV: 100%.
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.
Contraindicated if GFR < 30 m L/min; for GFR 30-50 m L/min: reduce dose and monitor electrolytes.
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 Class A: no adjustment; Class B: reduce dose by 50% and monitor; Class C: contraindicated.
Safety and efficacy in pediatric patients <18 years have not been established. Not recommended for use in children.
Not recommended; inadequate safety 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 with 1 tablet (hydrochlorothiazide 12.5 mg + methyldopa 125 mg) once daily; increase slowly; monitor for hypotension and electrolyte imbalance.
None
None
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
Sedation and drowsiness common; avoid driving or hazardous activities. Risk of Coombs-positive hemolytic anemia with methyldopa (discontinue if anemia develops). Hepatotoxicity and liver function abnormalities (discontinue if jaundice occurs). Orthostatic hypotension; caution in volume-depleted patients. Electrolyte imbalances (particularly hypokalemia, hyponatremia) with hydrochlorothiazide; monitor serum electrolytes. Sulfonamide cross-sensitivity possible. Exacerbation of systemic lupus erythematosus. Avoid abrupt withdrawal of methyldopa (may cause rebound hypertension).
Hypersensitivity to any component,Do not use with aliskiren in patients with diabetes
Active hepatic disease (cirrhosis, hepatitis) associated with methyldopa therapy; previous methyldopa-induced liver disorders. Anuria or hypersensitivity to thiazide diuretics or sulfonamide-derived drugs. Concomitant use with MAO inhibitors. Severe renal impairment (creatinine clearance <30 m L/min) or electrolyte depletion due to hydrochlorothiazide. Concurrent lithium therapy (risk of lithium toxicity).
Avoid grapefruit and grapefruit juice due to CYP3A4 inhibition increasing amlodipine levels. No other significant food interactions.
Avoid potassium supplements or salt substitutes containing potassium without consulting doctor. Limit alcohol intake. Avoid excessive grapefruit juice. Maintain adequate potassium intake through diet to prevent hypokalemia.
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.
Hydrochlorothiazide (HCTZ) is Pregnancy Category B in first trimester and Category D in second/third trimesters. Methyldopa (M) is Category B. HCTZ use in second/third trimester may cause fetal/neonatal effects including electrolyte disturbances, jaundice, thrombocytopenia, and possible fetal growth restriction. Methyldopa has not shown teratogenicity. Aldoril D50 (M 500mg/HCTZ 50mg) is not recommended during pregnancy, especially after first 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.
Both methyldopa and HCTZ are excreted in breast milk. Methyldopa M/P ratio approximately 1.0; HCTZ M/P ratio variable, small amounts. Use during breastfeeding may suppress lactation due to HCTZ diuretic effect. Monitor infant for signs of hypotension, electrolyte imbalance. Caution recommended; use only if clearly needed.
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.
Pregnancy-induced increase in plasma volume may reduce effectiveness of HCTZ, requiring dose adjustment. Methyldopa pharmacokinetics not significantly altered; however, increased clearance in pregnancy may require higher doses. In preeclampsia, dose adjustments may be needed. Avoid HCTZ in pregnancy if possible.
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.
ALDORIL D50 combines methyldopa and hydrochlorothiazide. Monitor for orthostatic hypotension, especially in volume-depleted patients. May cause positive Coombs test, hemolytic anemia, and lupus-like syndrome. Avoid in pheochromocytoma. Use caution in hepatic disease.
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 double up.,May cause dizziness or drowsiness; avoid driving until you know how it affects you.,Report unexplained fever, jaundice, or dark urine immediately.,Avoid sudden discontinuation; may cause rapid increase in blood pressure.,Stay hydrated but do not overhydrate; monitor for signs of electrolyte imbalance.
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 ALDORIL D50, 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.. ALDORIL D50 is a Antihypertensive Combination that works by Aldoril D50 is a combination of methyldopa and hydrochlorothiazide. Methyldopa is a centrally-acting alpha-2 adrenergic agonist that reduces sympathetic outflow from the brainstem, decreasing peripheral vascular resistance and blood pressure. Hydrochlorothiazide is a thiazide diuretic that inhibits sodium reabsorption in the distal convoluted tubule, reducing plasma volume and further lowering blood pressure.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between AZOR and ALDORIL D50 depend on the specific clinical indication. These are both Antihypertensive Combination agents 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 ALDORIL D50 is: 1 tablet (hydrochlorothiazide 25 mg + methyldopa 250 mg) orally twice daily; maximum dose: 2 tablets (50 mg + 500 mg) 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 ALDORIL D50 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. ALDORIL D50 is classified as Category C. Hydrochlorothiazide (HCTZ) is Pregnancy Category B in first trimester and Category D in second/third trimesters. Methyldopa (M) is Category B. HCTZ use in second/third trimester ma. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.