Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
SER-AP-ES vs ALDOCLOR-250
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).
Aldoclor-250 is a combination of methyldopa and chlorothiazide. Methyldopa is a centrally acting alpha-2 adrenergic agonist that reduces sympathetic outflow from the brain, decreasing peripheral vascular resistance and blood pressure. Chlorothiazide is a thiazide diuretic that inhibits sodium and chloride reabsorption in the distal convoluted tubule, increasing urinary output and reducing plasma volume.
Hypertension
Hypertension (first-line or adjunctive therapy),Off-label: Management of hypertensive crisis (as part of combination therapy)
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.
250 mg orally 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.
1.5-3 hours; prolonged in renal impairment (up to 20 hours with Cr Cl <10 m L/min).
Reserpine: extensively metabolized in liver; Hydralazine: hepatic acetylation (N-acetyltransferase); Hydrochlorothiazide: not metabolized, excreted unchanged.
Methyldopa: Primarily hepatic metabolism via catecholamine pathways; conjugated to sulfate and other metabolites. Chlorothiazide: Not extensively metabolized; excreted unchanged in urine.
Renal: 30-40% unchanged reserpine; 60-70% as metabolites (hydralazine: 50% renal, 15% fecal; hydrochlorothiazide: 95% renal unchanged).
Renal (70-80% unchanged), biliary/fecal (15-25% as metabolites); total clearance ~250 m L/min.
Reserpine: 40% bound (albumin); hydralazine: 87% bound; hydrochlorothiazide: 40-68% bound (albumin).
25-40% bound primarily to albumin and alpha-1-acid glycoprotein.
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.
0.6-1.0 L/kg; indicates distribution into total body water and some tissue binding.
Reserpine: 50% oral; hydralazine: 30-50% oral; hydrochlorothiazide: 65-75% oral.
70-90% (oral); 100% (IV).
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.
Cr Cl >50 m L/min: no adjustment; Cr Cl 10-50 m L/min: 250 mg once daily; Cr Cl <10 m L/min: 250 mg every 48 hours
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 A: no adjustment; Child-Pugh B: use with caution, reduce dose by 50%; Child-Pugh C: avoid use
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 at lower end of dosing range; monitor renal function closely; adjust dose based on Cr Cl
None
None explicitly listed. However, methyldopa carries a warning for hepatotoxicity and hemolytic anemia; chlorothiazide carries a warning for electrolyte disturbances and hypersensitivity reactions.
Reserpine: May cause depression, peptic ulcer activation.,Hydralazine: Drug-induced lupus, peripheral neuritis (pyridoxine deficiency), tachycardia.,Hydrochlorothiazide: Electrolyte imbalance, hyperuricemia, photosensitivity.
Hepatotoxicity (methyldopa), hemolytic anemia, positive direct Coombs test, sedation, depression, bradycardia, orthostatic hypotension, electrolyte imbalance (hypokalemia, hyponatremia, hypomagnesemia), hyperuricemia, hyperglycemia, photosensitivity, lupus-like syndrome, and hypersensitivity reactions.
Hypersensitivity to any component,History of depression (reserpine),Severe renal impairment (hydralazine, hydrochlorothiazide),Anuria (hydrochlorothiazide)
Active hepatic disease, history of previous methyldopa-induced liver dysfunction, hemolytic anemia associated with methyldopa, anuria, hypersensitivity to methyldopa, chlorothiazide, or sulfonamide-derived drugs, severe renal impairment (Cr Cl <30 m L/min), and concomitant therapy with MAO inhibitors.
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.
Avoid high-potassium foods (bananas, oranges, spinach) unless specifically advised; chlorothiazide may cause potassium loss, but methyldopa can cause potassium retention. Avoid excessive alcohol intake as it may potentiate hypotension. Take with food to reduce gastrointestinal upset. May decrease glucose tolerance; monitor in diabetic patients.
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.
FDA Pregnancy Category D. First trimester: Associated with cardiovascular defects (e.g., VSD), neural tube defects, and oral clefts. Second and third trimesters: Fetal nephrotoxicity (oligohydramnios, renal failure), premature closure of ductus arteriosus, pulmonary hypertension, and intracranial hemorrhage. Avoid in third trimester.
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.
Chlorothiazide is excreted in breast milk; M/P ratio unknown. Can suppress lactation. Use only if maternal benefit outweighs potential infant risks (e.g., electrolyte disturbances, thrombocytopenia).
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.
Increased volume of distribution and GFR in pregnancy may necessitate higher doses for equivalent effect. Start at lowest effective dose; titrate based on BP response. Monitor for hypokalemia and metabolic alkalosis.
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.
Aldoclor-250 is a combination of methyldopa (250mg) and chlorothiazide. Methyldopa can cause a positive direct Coombs test (10-20% of patients) which may interfere with blood cross-matching; obtain a hematocrit and Coombs test before therapy and at 6 and 12 months. Chlorothiazide may cause hypokalemia; monitor potassium and consider potassium supplementation. Onset of methyldopa is 3-6 hours; delay full effect for 48-72 hours. Avoid use in patients with active liver disease or history of previous methyldopa-induced liver dysfunction.
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; do not skip doses or stop suddenly.,May cause drowsiness or dizziness; avoid driving or operating machinery until you know how it affects you.,Rise slowly from sitting or lying to prevent lightheadedness.,Report any unexplained fever, jaundice, or dark urine immediately.,Use sun protection; this drug may increase sensitivity to sunlight.,Do not use potassium supplements or salt substitutes without consulting your doctor.,If you miss a dose, take it as soon as you remember unless it's near the next dose; do not double.
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 ALDOCLOR-250, 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).. ALDOCLOR-250 is a Antihypertensive Combination (Central Alpha Agonist and Thiazide Diuretic) that works by Aldoclor-250 is a combination of methyldopa and chlorothiazide. Methyldopa is a centrally acting alpha-2 adrenergic agonist that reduces sympathetic outflow from the brain, decreasing peripheral vascular resistance and blood pressure. Chlorothiazide is a thiazide diuretic that inhibits sodium and chloride reabsorption in the distal convoluted tubule, increasing urinary output and reducing plasma volume.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between SER-AP-ES and ALDOCLOR-250 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 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 ALDOCLOR-250 is: 250 mg orally 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 ALDOCLOR-250 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. ALDOCLOR-250 is classified as Category C. FDA Pregnancy Category D. First trimester: Associated with cardiovascular defects (e.g., VSD), neural tube defects, and oral clefts. Second and third trimesters: Fetal nephrotoxici. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.