Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
DIUPRES-500 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
Diupres-500 is a combination of chlorothiazide, a thiazide diuretic, and reserpine, a Rauwolfia alkaloid. Chlorothiazide inhibits the Na+-Cl- symporter in the distal convoluted tubule of the kidney, reducing sodium and chloride reabsorption and increasing water excretion. Reserpine depletes catecholamines from central and peripheral nerve terminals by blocking vesicular monoamine transporter 2 (VMAT2), leading to decreased sympathetic outflow and vasodilation.
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.
Essential hypertension,Edema associated with congestive heart failure, hepatic cirrhosis, and renal dysfunction
Hypertension (first-line or second-line therapy),Hypertensive urgency (off-label)
Oral, 1 tablet (hydrochlorothiazide 50 mg + reserpine 0.125 mg) once daily, increased up to 2 tablets per day if needed.
1 tablet (hydrochlorothiazide 25 mg + methyldopa 250 mg) orally twice daily; maximum dose: 2 tablets (50 mg + 500 mg) twice daily.
Reserpine: 50-100 hours (prolonged; clinical effect persists for days due to irreversible MAO depletion). Hydrochlorothiazide: 6-15 hours (biphasic; terminal phase reflects renal elimination).
3–6 hours (terminal elimination half-life); clinical context: requires twice-daily dosing for sustained blood pressure control; prolonged in renal impairment.
Chlorothiazide is not metabolized and is excreted unchanged in urine. Reserpine is extensively metabolized in the liver via CYP450 enzymes to inactive metabolites.
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: ~50% (primarily hydrochlorothiazide), Fecal: ~50% (primarily reserpine).
Renal: 50% as unchanged drug and 20% as metabolites; biliary/fecal: ~25% (as metabolites); total renal clearance accounts for ~70% of elimination.
Reserpine: ~96% (albumin). Hydrochlorothiazide: ~68% (albumin).
~20% bound to albumin; minimal binding to other plasma proteins.
Reserpine: 4-8 L/kg (extensive tissue binding, especially lipid-rich and CNS). Hydrochlorothiazide: 0.8-1.5 L/kg (distributes into extracellular fluid).
0.2–0.3 L/kg (moderately low Vd, indicating limited extravascular distribution and predominantly plasma water distribution).
Oral: Reserpine ~50% (variable due to first-pass metabolism); Hydrochlorothiazide ~65-70% (dose-dependent).
Oral: 30–40% (due to extensive first-pass metabolism); IV: 100%.
GFR 30-50 m L/min: use with caution, reduce dose if needed. GFR <30 m L/min: contraindicated.
Contraindicated if GFR < 30 m L/min; for GFR 30-50 m L/min: reduce dose and monitor electrolytes.
Child-Pugh A: no adjustment. Child-Pugh B or C: contraindicated due to risk of hepatic encephalopathy.
Child-Pugh Class A: no adjustment; Class B: reduce dose by 50% and monitor; Class C: contraindicated.
Not recommended; safety and efficacy not established.
Not recommended; inadequate safety data.
Initiate at lowest dose (50 mg hydrochlorothiazide + 0.125 mg reserpine) once daily; monitor electrolytes, renal function, and CNS depression.
Start with 1 tablet (hydrochlorothiazide 12.5 mg + methyldopa 125 mg) once daily; increase slowly; monitor for hypotension and electrolyte imbalance.
None
None
Electrolyte imbalance: Monitor potassium, sodium, magnesium; hypokalemia increases risk of digitalis toxicity,Mental depression: Reserpine may cause severe depression, especially in patients with history,Sulfonamide cross-sensitivity: Chlorothiazide may cause allergic reactions in patients with sulfonamide allergy,Azotemia: May precipitate renal impairment in patients with kidney disease,Orthostatic hypotension: Common with reserpine, especially after initial doses
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 chlorothiazide, reserpine, or sulfonamide-derived drugs,Anuria,Active peptic ulcer disease,Ulcerative colitis,History of mental depression (especially with suicidal tendencies),Electroconvulsive therapy,Pheochromocytoma
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 excessive intake of high-potassium foods (e.g., bananas, oranges, spinach) due to increased potassium retention risk with hydrochlorothiazide. Limit alcohol consumption as it may enhance blood pressure-lowering effects and cause dizziness. Maintain adequate hydration but avoid potassium-containing salt substitutes.
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.
First trimester: Risk of fetal hydantoin syndrome (craniofacial defects, hypoplastic nails, growth deficiency). Second trimester: Increased risk of neural tube defects, congenital heart defects. Third trimester: Risk of neonatal hemorrhage and hepatic enzyme induction.
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.
Excreted in breast milk; M/P ratio approximately 0.2-0.4. Consider risk of infant sedation and poor feeding. Weigh benefits of breastfeeding against potential adverse effects.
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.
Increased clearance due to hepatic induction and increased volume of distribution; may require up to 50% dose increase. Monitor free phenytoin levels as protein binding decreases. Adjust dose to maintain therapeutic levels.
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.
DIUPRES-500 contains hydrochlorothiazide 50 mg and reserpine 0.125 mg. Monitor serum potassium and renal function regularly. Reserpine may cause bradycardia and depression; use with caution in patients with history of peptic ulcer disease. Avoid abrupt discontinuation due to risk of withdrawal hypertension.
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 this medication exactly as prescribed, usually once daily in the morning.,Do not stop taking this medication suddenly without consulting your doctor.,This drug may make you urinate more frequently; avoid taking it before bedtime.,Report any symptoms of depression, unusual fatigue, or slow heart rate to your doctor.,Avoid prolonged sun exposure and use sunscreen; this medication can increase sensitivity to sunlight.
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 DIUPRES-500 vs ALDORIL D50, answered by our medical review team.
DIUPRES-500 is a Antihypertensive Combination that works by Diupres-500 is a combination of chlorothiazide, a thiazide diuretic, and reserpine, a Rauwolfia alkaloid. Chlorothiazide inhibits the Na+-Cl- symporter in the distal convoluted tubule of the kidney, reducing sodium and chloride reabsorption and increasing water excretion. Reserpine depletes catecholamines from central and peripheral nerve terminals by blocking vesicular monoamine transporter 2 (VMAT2), leading to decreased sympathetic outflow and vasodilation.. 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 DIUPRES-500 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 DIUPRES-500 is: Oral, 1 tablet (hydrochlorothiazide 50 mg + reserpine 0.125 mg) once daily, increased up to 2 tablets per day if needed.. 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 DIUPRES-500 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. DIUPRES-500 is classified as Category C. First trimester: Risk of fetal hydantoin syndrome (craniofacial defects, hypoplastic nails, growth deficiency). Second trimester: Increased risk of neural tube defects, congenital . 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.