Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
APRESOLINE-ESIDRIX vs ALDORIL D30
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Apresoline (hydralazine) is a direct-acting vasodilator that relaxes arteriolar smooth muscle via unknown mechanism; Esidrix (hydrochlorothiazide) is a thiazide diuretic that inhibits sodium and chloride reabsorption in the distal convoluted tubule.
Aldoril D30 is a combination of methyldopa, a centrally acting alpha-2 adrenergic agonist that reduces sympathetic outflow, and hydrochlorothiazide, a thiazide diuretic that inhibits the sodium-chloride symporter in the distal convoluted tubule, decreasing plasma volume and peripheral resistance.
Hypertension
Hypertension
Hydralazine (Apresoline): Oral, initial 10 mg 4 times daily for first 2-4 days, then increase to 25 mg 4 times daily for first week, then 50 mg 4 times daily thereafter. Maximum daily dose: 300 mg. Hydrochlorothiazide (Esidrix): Oral, initial 12.5-25 mg once daily, may increase to 50 mg once daily if needed.
Oral: 1 tablet (hydrochlorothiazide 30 mg / methyldopa 500 mg) twice daily; maximum dose: 2 tablets twice daily.
Hydralazine: 2-8 h (prolonged in renal impairment); Hydrochlorothiazide: 6-15 h (mean 10 h, increased in renal failure).
Terminal elimination half-life of hydrochlorothiazide is 6-15 hours; methyldopa half-life is 1.8 hours (normal renal function). In renal impairment, half-life of both components is prolonged.
Hydralazine undergoes N-acetylation (polymorphic, NAT2) and CYP450; hydrochlorothiazide is not extensively metabolized (excreted unchanged in urine).
Methyldopa is metabolized by conjugation (catechol-O-methyltransferase) and hepatic sulfation; hydrochlorothiazide is not extensively metabolized and is excreted unchanged by the kidney.
Renal: Hydralazine 85-90% as metabolites, 5-10% unchanged; Hydrochlorothiazide 95% as unchanged drug. Biliary/fecal: Hydralazine <10%.
Renal: approximately 50% as parent drug and metabolites; biliary/fecal: minimal, less than 5%.
Hydralazine: 85-90% (primarily albumin); Hydrochlorothiazide: 40-68% (albumin).
Methyldopa: <10% bound to plasma proteins; hydrochlorothiazide: 40-68% bound to albumin.
Hydralazine: 1.5-1.8 L/kg (extensive tissue distribution); Hydrochlorothiazide: 0.83-1.2 L/kg.
Methyldopa: Vd 0.2-0.3 L/kg (distributes into tissues, crosses placenta); hydrochlorothiazide: Vd 0.75-1.5 L/kg (extensively distributed, does not cross blood-brain barrier significantly).
Hydralazine: 30-50% (oral, extensive first-pass metabolism; slower in slow acetylators); Hydrochlorothiazide: 65-75% (oral).
Oral bioavailability of methyldopa is approximately 25% (variable, influenced by gut metabolism); hydrochlorothiazide bioavailability is 65-75%.
Hydralazine: No adjustment for GFR >10 m L/min; for GFR <10 m L/min, reduce dose to 30-50% of normal. Hydrochlorothiazide: Not effective if GFR <30 m L/min; use alternative diuretic. For Cr Cl 30-50 m L/min, reduce dose or interval.
GFR 30-60 m L/min: reduce dose by 50%; GFR <30 m L/min: not recommended.
Hydralazine: Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 50%; Child-Pugh C: contraindicated. Hydrochlorothiazide: Caution in severe liver disease due to electrolyte imbalances; no specific dose adjustment defined; use with monitoring.
Child-Pugh Class B or C: contraindicated; use not recommended.
Hydralazine: Oral, initial 0.75-1 mg/kg/day in 2-4 divided doses, increase over 3-4 weeks to maximum 7.5 mg/kg/day or 200 mg/day. Hydrochlorothiazide: Oral, 1-2 mg/kg/day in 2 divided doses; maximum 6 mg/kg/day or 50 mg/day.
Not recommended for use in pediatric patients due to lack of safety and efficacy data.
Hydralazine: Start at lower end of dosing range (10 mg 4 times daily) and titrate slowly due to increased sensitivity and risk of hypotension. Hydrochlorothiazide: Start at 12.5 mg once daily, monitor renal function and electrolytes more frequently.
Start with lowest dose; monitor for hypotension, electrolyte imbalance, and CNS effects; consider reduced initial dose.
No black box warning specifically for the combination; hydralazine carries a warning for drug-induced lupus erythematosus.
None
Lupus erythematosus-like syndrome (hydralazine),Hypotension,Myocardial infarction (exacerbation due to reflex tachycardia),Electrolyte imbalances (hypokalemia, hyponatremia) from thiazide,Hyperuricemia,Sulfonamide allergy cross-reactivity (thiazide)
May cause hemolytic anemia, liver disorders, positive Coombs test, sedation, depression, and hypersensitivity reactions. Hydrochlorothiazide may cause electrolyte imbalance, hyperuricemia, photosensitivity, and exacerbation of systemic lupus erythematosus. Use with caution in renal impairment, hepatic disease, and in patients with a history of drug-induced hemolytic anemia.
Hypersensitivity to hydralazine or hydrochlorothiazide,Anuria,Concomitant use with MAO inhibitors,Rheumatic mitral valve disease (hydralazine)
Active hepatic disease, history of previous methyldopa therapy-associated liver disorders; anuria; hypersensitivity to methyldopa, hydrochlorothiazide, or sulfonamide-derived drugs.
Avoid natural licorice (glycyrrhizin) as it can worsen hypokalemia and reduce antihypertensive effect. High-sodium foods should be limited as they can counteract the blood pressure-lowering effect. Grapefruit juice may enhance hydralazine absorption; consistent consumption is advised if intake is routine. Alcohol may potentiate orthostatic hypotension and dizziness.
Food may decrease absorption of methyldopa. Avoid excessive intake of high-potassium foods (e.g., bananas, oranges) unless directed. Hydrochlorothiazide may cause potassium depletion; maintain adequate dietary potassium. Avoid natural licorice as it can worsen hypokalemia.
APRESOLINE-ESIDRIX (hydralazine/hydrochlorothiazide). First trimester: Hydrochlorothiazide (HCTZ) may cause fetal or neonatal jaundice, thrombocytopenia, and possibly other adverse reactions. Hydralazine has been associated with minor anomalies in animal studies but no well-controlled human studies; risk cannot be ruled out. Second/third trimester: Maternal hypotension may reduce uterine blood flow; HCTZ may cause fetal electrolyte disturbances, thrombocytopenia, and jaundice. Avoid use for edema in pregnancy; use only if clearly needed.
First trimester: Limited data; no clear evidence of major malformations but methyldopa crosses placenta. Second and third trimesters: Associated with reduced placental perfusion; possible fetal bradycardia and neonatal hypotension. Hydrochlorothiazide may cause fetal/neonatal jaundice, thrombocytopenia, and electrolyte disturbances.
Hydralazine: M/P ratio unknown; excreted in breast milk in small amounts; unlikely to cause adverse effects in infant. Hydrochlorothiazide: M/P ratio ~0.3; excreted in breast milk; may suppress lactation; use caution, especially if high doses or dehydration.
Methyldopa is excreted in breast milk in low concentrations; M/P ratio approximately 0.2. Hydrochlorothiazide is excreted in minimal amounts; may suppress lactation. Consider risks versus benefits.
Dose adjustments not typically required; however, pregnancy may alter pharmacokinetics (increased volume of distribution, increased renal clearance). Use lowest effective dose; monitor response. Avoid HCTZ for routine edema; use only if other diuretics contraindicated. Start with low doses and titrate slowly.
Methyldopa: Pregnancy-induced plasma volume expansion may require dose titration; monitor blood pressure and adjust accordingly. Hydrochlorothiazide: Often avoided in pregnancy due to volume depletion risks; if used, monitor electrolytes and renal function, no pharmacokinetic data necessitate routine dose adjustment.
APRESOLINE-ESIDRIX is a fixed-dose combination of hydralazine (vasodilator) and hydrochlorothiazide (thiazide diuretic). Monitor for reflex tachycardia and fluid retention with hydralazine; hypokalemia, hyponatremia, and hyperuricemia with hydrochlorothiazide. Use with caution in severe renal impairment (Cr Cl <30 m L/min) and coronary artery disease. May cause lupus-like syndrome with prolonged high-dose hydralazine (usually >200 mg/day). Administer with food to reduce GI upset.
ALDORIL D30 combines methyldopa (central alpha-2 agonist) and hydrochlorothiazide (thiazide diuretic). Monitor for orthostatic hypotension, especially at initiation. Taper not needed for methyldopa but discontinue if fever or liver dysfunction occurs. Interferes with urinary catecholamine measurements (false elevation). Hydrochlorothiazide may cause hyponatremia, hypokalemia, and hyperglycemia; check electrolytes and glucose periodically.
Take this medication exactly as prescribed, usually once daily in the morning to avoid nighttime urination.,You may experience dizziness or lightheadedness, especially when standing up quickly; rise slowly from sitting or lying down.,Report any unexplained joint pain, rash, fever, or fatigue, as these may be signs of a lupus-like reaction.,Avoid alcohol, which can increase blood pressure-lowering effects and dizziness.,Drink adequate fluids unless otherwise advised by your doctor, but do not increase salt intake without consulting your healthcare provider.,Do not stop taking this medication abruptly, as sudden withdrawal may cause a rapid increase in blood pressure.
Take exactly as prescribed, preferably with food to reduce stomach upset.,Rise slowly from sitting or lying down to prevent dizziness.,This drug may make you drowsy; avoid driving or operating machinery until you know how it affects you.,Report fever, unexplained fatigue, jaundice, or dark urine immediately.,Weigh yourself daily and report rapid weight gain or swelling.,Limit alcohol intake as it can increase side effects.,Do not use salt substitutes containing potassium without consulting your doctor.
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 APRESOLINE-ESIDRIX vs ALDORIL D30, answered by our medical review team.
APRESOLINE-ESIDRIX is a Antihypertensive that works by Apresoline (hydralazine) is a direct-acting vasodilator that relaxes arteriolar smooth muscle via unknown mechanism; Esidrix (hydrochlorothiazide) is a thiazide diuretic that inhibits sodium and chloride reabsorption in the distal convoluted tubule.. ALDORIL D30 is a Antihypertensive Combination that works by Aldoril D30 is a combination of methyldopa, a centrally acting alpha-2 adrenergic agonist that reduces sympathetic outflow, and hydrochlorothiazide, a thiazide diuretic that inhibits the sodium-chloride symporter in the distal convoluted tubule, decreasing plasma volume and peripheral resistance.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between APRESOLINE-ESIDRIX and ALDORIL D30 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 APRESOLINE-ESIDRIX is: Hydralazine (Apresoline): Oral, initial 10 mg 4 times daily for first 2-4 days, then increase to 25 mg 4 times daily for first week, then 50 mg 4 times daily thereafter. Maximum daily dose: 300 mg. Hydrochlorothiazide (Esidrix): Oral, initial 12.5-25 mg once daily, may increase to 50 mg once daily if needed.. The standard adult dose of ALDORIL D30 is: Oral: 1 tablet (hydrochlorothiazide 30 mg / methyldopa 500 mg) twice daily; maximum dose: 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 APRESOLINE-ESIDRIX and ALDORIL D30 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. APRESOLINE-ESIDRIX is classified as Category C. APRESOLINE-ESIDRIX (hydralazine/hydrochlorothiazide). First trimester: Hydrochlorothiazide (HCTZ) may cause fetal or neonatal jaundice, thrombocytopenia, and possibly other adverse. ALDORIL D30 is classified as Category C. First trimester: Limited data; no clear evidence of major malformations but methyldopa crosses placenta. Second and third trimesters: Associated with reduced placental perfusion; p. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.