Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
DIUPRES-500 vs ALDORIL 15
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.
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 and chloride reabsorption in the distal convoluted tubule, reducing plasma volume and cardiac output.
Essential hypertension,Edema associated with congestive heart failure, hepatic cirrhosis, and renal dysfunction
Hypertension
Oral, 1 tablet (hydrochlorothiazide 50 mg + reserpine 0.125 mg) once daily, increased up to 2 tablets per day if needed.
1 tablet (hydrochlorothiazide 15 mg, methyldopa 250 mg) orally twice daily; increase as needed up to 2 tablets 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).
Terminal half-life: 12–17 hours; clinical context: steady-state achieved within 2–3 days; effect persists 12–24 hours
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 metabolized in the liver via conjugation and O-methylation; active metabolites include methyldopamine and methylnorepinephrine. Hydrochlorothiazide is not significantly metabolized and is excreted unchanged in urine.
Renal: ~50% (primarily hydrochlorothiazide), Fecal: ~50% (primarily reserpine).
Renal: ~70% unchanged; biliary/fecal: ~30% as metabolites
Reserpine: ~96% (albumin). Hydrochlorothiazide: ~68% (albumin).
~90%, primarily to albumin
Reserpine: 4-8 L/kg (extensive tissue binding, especially lipid-rich and CNS). Hydrochlorothiazide: 0.8-1.5 L/kg (distributes into extracellular fluid).
2–4 L/kg; clinical meaning: extensive tissue distribution, concentrating in vascular smooth muscle
Oral: Reserpine ~50% (variable due to first-pass metabolism); Hydrochlorothiazide ~65-70% (dose-dependent).
Oral: 50–60% (extensive first-pass metabolism)
GFR 30-50 m L/min: use with caution, reduce dose if needed. GFR <30 m L/min: contraindicated.
GFR 30-50 m L/min: maximum 1 tablet twice daily. GFR <30 m L/min: avoid use.
Child-Pugh A: no adjustment. Child-Pugh B or C: contraindicated due to risk of hepatic encephalopathy.
Child-Pugh A: caution, reduce dose. Child-Pugh B: avoid. Child-Pugh C: contraindicated.
Not recommended; safety and efficacy not established.
Not recommended for pediatric use; safety in children under 12 years not established.
Initiate at lowest dose (50 mg hydrochlorothiazide + 0.125 mg reserpine) once daily; monitor electrolytes, renal function, and CNS depression.
Start with 1 tablet once daily; monitor for hypotension and electrolyte imbalance. Reduce initial dose by 50%.
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, usually transient; may impair ability to drive or operate heavy machinery.,Positive Coombs test with hemolytic anemia (rare); monitor hematocrit and Coombs test.,Hepatotoxicity (hepatic necrosis) with fever, jaundice; discontinue if liver abnormalities occur.,Fluid and electrolyte imbalance (hypokalemia, hyponatremia, hypercalcemia) due to thiazide.,May precipitate gout in hyperuricemic patients.,May exacerbate systemic lupus erythematosus.
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 (e.g., acute hepatitis, cirrhosis),Prior methyldopa therapy associated with liver disorders,Hypersensitivity to methyldopa or hydrochlorothiazide,Anuria,Sulfonamide allergy (cross-sensitivity with thiazides)
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 high-sodium foods as they can reduce antihypertensive efficacy. Thiazides may cause hypokalemia; increase dietary potassium (bananas, orange juice) unless contraindicated. Alcohol may enhance orthostatic hypotension.
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.
First trimester: No increased risk of major malformations based on limited human data; animal studies show no teratogenicity at clinically relevant doses. Second/third trimesters: Fetal and neonatal adverse effects including oligohydramnios, fetal renal dysfunction, skull ossification delay, and hypotension in the neonate. Avoid use after 20 weeks gestation unless no alternative.
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.
Methyldopa and hydrochlorothiazide are excreted into human milk. M/P ratio for methyldopa is approximately 0.5-1.0; for hydrochlorothiazide, M/P ratio ~2.0. Methyldopa is considered compatible with breastfeeding. Hydrochlorothiazide may suppress lactation and cause neonatal electrolyte disturbances. Use with caution; monitor infant for signs of diuresis or electrolyte imbalance.
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.
Pharmacokinetic changes in pregnancy may include increased volume of distribution and enhanced renal clearance. No specific dose adjustment routine is recommended; dosing should be guided by clinical response. Methyldopa starting dose 250 mg twice daily, titrated to effect. Hydrochlorothiazide dose not typically adjusted, but caution due to potential volume depletion.
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 15 (methyldopa 250mg + hydrochlorothiazide 15mg) is rarely used due to superior alternatives. Monitor for hepatotoxicity, hemolytic anemia, and lupus-like syndrome. Titrate slowly to avoid sedation. Contraindicated in active liver disease, pheochromocytoma, and anuria.
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.
May cause drowsiness; avoid driving until tolerance develops.,Report unexplained fever, jaundice, or dark urine immediately.,Take at bedtime to minimize sedation.,Avoid sudden discontinuation; follow prescribed tapering schedule.,Use sun protection; thiazides increase photosensitivity.
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 15, 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 15 is a Antihypertensive Combination that works by 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 and chloride reabsorption in the distal convoluted tubule, reducing plasma volume and cardiac output.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between DIUPRES-500 and ALDORIL 15 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 15 is: 1 tablet (hydrochlorothiazide 15 mg, methyldopa 250 mg) orally twice daily; increase as needed up to 2 tablets 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 15 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 15 is classified as Category C. First trimester: No increased risk of major malformations based on limited human data; animal studies show no teratogenicity at clinically relevant doses. Second/third trimesters: . Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.