Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
SER-AP-ES 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
SER-AP-ES is a combination product containing reserpine (depletes catecholamines from adrenergic nerve endings), hydralazine (direct vasodilation via smooth muscle relaxation), and hydrochlorothiazide (thiazide diuretic that inhibits sodium reabsorption in distal tubules).
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
SER-AP-ES is a combination antihypertensive tablet containing reserpine 0.1 mg, hydralazine hydrochloride 25 mg, and hydrochlorothiazide 15 mg. Usual adult dose: one tablet orally twice daily. Increase as needed to a maximum of two tablets twice daily.
Oral: 1 tablet (hydrochlorothiazide 30 mg / methyldopa 500 mg) twice daily; maximum dose: 2 tablets twice daily.
Reserpine: 50-100h (terminal); hydralazine: 2-8h (slow acetylators 4-8h, fast 2-4h); hydrochlorothiazide: 6-15h. Context: reserpine's long t½ accounts for prolonged effects; hydralazine requires dose adjustment for acetylator status.
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.
Reserpine: extensively metabolized in liver; Hydralazine: hepatic acetylation (N-acetyltransferase); Hydrochlorothiazide: not metabolized, excreted unchanged.
Methyldopa is metabolized by conjugation (catechol-O-methyltransferase) and hepatic sulfation; hydrochlorothiazide is not extensively metabolized and is excreted unchanged by the kidney.
Renal: 30-40% unchanged reserpine; 60-70% as metabolites (hydralazine: 50% renal, 15% fecal; hydrochlorothiazide: 95% renal unchanged).
Renal: approximately 50% as parent drug and metabolites; biliary/fecal: minimal, less than 5%.
Reserpine: 40% bound (albumin); hydralazine: 87% bound; hydrochlorothiazide: 40-68% bound (albumin).
Methyldopa: <10% bound to plasma proteins; hydrochlorothiazide: 40-68% bound to albumin.
Reserpine: 6 L/kg; hydralazine: 1.6 L/kg; hydrochlorothiazide: 0.8 L/kg. Clinical meaning: reserpine extensive tissue distribution (fat, brain); hydralazine moderate; thiazide limited to extracellular fluid.
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).
Reserpine: 50% oral; hydralazine: 30-50% oral; hydrochlorothiazide: 65-75% oral.
Oral bioavailability of methyldopa is approximately 25% (variable, influenced by gut metabolism); hydrochlorothiazide bioavailability is 65-75%.
Hydrochlorothiazide: Contraindicated if Cr Cl < 30 m L/min. For Cr Cl 30-50 m L/min: reduce dose of hydrochlorothiazide to 12.5 mg daily; consider using individual components. Reserpine and hydralazine: no specific GFR-based adjustment, but use with caution if severe renal impairment.
GFR 30-60 m L/min: reduce dose by 50%; GFR <30 m L/min: not recommended.
Reserpine and hydralazine are contraindicated in severe hepatic impairment. For Child-Pugh A or B: no specific dose adjustment but monitor closely. For Child-Pugh C: avoid use.
Child-Pugh Class B or C: contraindicated; use not recommended.
Not recommended for pediatric use due to lack of safety and efficacy data. Use individual components with appropriate weight-based dosing if needed.
Not recommended for use in pediatric patients due to lack of safety and efficacy data.
Initiate with one tablet orally once daily. Titrate slowly due to increased risk of hypotension, electrolyte disturbances, and central nervous system effects. Monitor renal function and electrolytes closely.
Start with lowest dose; monitor for hypotension, electrolyte imbalance, and CNS effects; consider reduced initial dose.
None
None
Reserpine: May cause depression, peptic ulcer activation.,Hydralazine: Drug-induced lupus, peripheral neuritis (pyridoxine deficiency), tachycardia.,Hydrochlorothiazide: Electrolyte imbalance, hyperuricemia, photosensitivity.
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 any component,History of depression (reserpine),Severe renal impairment (hydralazine, hydrochlorothiazide),Anuria (hydrochlorothiazide)
Active hepatic disease, history of previous methyldopa therapy-associated liver disorders; anuria; hypersensitivity to methyldopa, hydrochlorothiazide, or sulfonamide-derived drugs.
Avoid foods high in sodium to prevent bloating and counteract diuretic effect. Excessive potassium intake (e.g., salt substitutes, bananas, oranges) may be needed if hypokalemia is present, but monitor potassium levels. Grapefruit juice may alter absorption; avoid large amounts. Alcohol increases risk of hypotension and sedation; avoid concurrent use.
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.
SER-AP-ES is a combination product containing reserpine, hydralazine, and hydrochlorothiazide. Reserpine: crosses placenta, animal studies show fetal abnormalities (skeletal and CNS) in high doses; first trimester risk uncertain, second/third trimester associated with neonatal respiratory depression, bradycardia, hypothermia. Hydralazine: animal studies show cleft palate, skeletal malformations; human data limited; risk not excluded. Hydrochlorothiazide: associated with neonatal thrombocytopenia, electrolyte disturbances, and possibly fetal or neonatal jaundice; second/third trimester use may cause fetal hypoxia and placental insufficiency. Overall, avoid in pregnancy unless benefit outweighs risk; first trimester highest risk.
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.
Reserpine: excreted into breast milk; M/P ratio ~0.5; may cause galactorrhea, breast engorgement, or adverse effects in infant (drowsiness, nasal congestion). Hydralazine: present in breast milk in low amounts (M/P ratio ~1); considered compatible but monitor infant for hypotension. Hydrochlorothiazide: excreted in breast milk in low concentrations (M/P ratio ~0.5); may suppress lactation and cause electrolyte imbalance in infant. Use caution; avoid if possible or monitor infant.
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.
Pharmacokinetic changes: increased plasma volume and renal clearance may reduce drug concentrations; hydralazine undergoes acetylation (polymorphic), may require dose increase. Reserpine: no data, but similar adjustments not typically recommended. Hydrochlorothiazide: reduced efficacy due to volume expansion; avoid in pregnancy-induced hypertension. In severe hypertension, hydralazine may be used IV with cautious titration; oral adjustments: start low, titrate based on response.
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.
SER-AP-ES is a combination antihypertensive containing reserpine, hydralazine, and hydrochlorothiazide. Reserpine depletes catecholamines centrally and peripherally; may cause depression, nasal congestion, and bradycardia. Hydralazine is a direct vasodilator; can cause drug-induced lupus-like syndrome, especially in slow acetylators. Hydrochlorothiazide is a thiazide diuretic; monitor for hypokalemia, hyponatremia, and hyperglycemia. Avoid use in patients with depression, peptic ulcer disease, or history of SLE. Titrate slowly due to reserpine's cumulative effect.
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 exactly as prescribed; do not stop suddenly as this may cause rapid rise in blood pressure.,Avoid over-the-counter cold or allergy medications without consulting your doctor.,Report symptoms of depression, mood changes, or suicidal thoughts immediately.,May cause dizziness or drowsiness; avoid driving until you know how this medication affects you.,Do not consume alcohol; it may increase side effects.,Monitor your blood pressure regularly and keep a log.,Stay hydrated but avoid excessive salt intake.,Report any unexplained fever, joint pain, or skin rash; may be signs of lupus-like reaction.,This medication may increase blood sugar; monitor if diabetic.
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 SER-AP-ES vs ALDORIL D30, answered by our medical review team.
SER-AP-ES is a Antihypertensive Combination that works by SER-AP-ES is a combination product containing reserpine (depletes catecholamines from adrenergic nerve endings), hydralazine (direct vasodilation via smooth muscle relaxation), and hydrochlorothiazide (thiazide diuretic that inhibits sodium reabsorption in distal tubules).. 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 SER-AP-ES and ALDORIL D30 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 SER-AP-ES is: SER-AP-ES is a combination antihypertensive tablet containing reserpine 0.1 mg, hydralazine hydrochloride 25 mg, and hydrochlorothiazide 15 mg. Usual adult dose: one tablet orally twice daily. Increase as needed to a maximum of two tablets twice daily.. 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 SER-AP-ES 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. SER-AP-ES is classified as Category C. SER-AP-ES is a combination product containing reserpine, hydralazine, and hydrochlorothiazide. Reserpine: crosses placenta, animal studies show fetal abnormalities (skeletal and CN. 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.