Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
ALDORIL 15 vs ARAKODA
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
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.
ARAKODA (tafenoquine) is an 8-aminoquinoline antimalarial agent that inhibits the conversion of Plasmodium protozoa from liver stage to blood stage, thereby preventing relapses. Its exact mechanism may involve interference with electron transport or generation of reactive oxygen species.
Hypertension
Radical cure (prevention of relapse) of Plasmodium vivax malaria in patients aged 16 years and older who are receiving appropriate antimalarial therapy for acute P. vivax infection
1 tablet (hydrochlorothiazide 15 mg, methyldopa 250 mg) orally twice daily; increase as needed up to 2 tablets twice daily.
400 mg orally once daily for 3 days, then 200 mg once daily for maintenance (up to 12 months).
Terminal half-life: 12–17 hours; clinical context: steady-state achieved within 2–3 days; effect persists 12–24 hours
Terminal elimination half-life: approximately 14-16 days (range 12-19 days) in healthy adults; this long half-life is due to extensive tissue distribution and slow release from tissues, providing prophylactic coverage for up to 4 weeks after a single dose.
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.
Primarily metabolized by CYP2D6 and monoamine oxidase (MAO). Tafenoquine undergoes extensive metabolism including N-dealkylation and oxidation.
Renal: ~70% unchanged; biliary/fecal: ~30% as metabolites
Biliary/fecal: ~90% unchanged; renal: <1% unchanged (dose-proportional urinary excretion of tafenoquine is minimal, with most eliminated via feces as unchanged drug and minor metabolites).
~90%, primarily to albumin
~99.5% bound to human serum albumin (HSA); binding is high and saturable, with unbound fraction slightly increasing at high concentrations.
2–4 L/kg; clinical meaning: extensive tissue distribution, concentrating in vascular smooth muscle
Apparent Vd: ~2000 L (or ~24-30 L/kg based on 70 kg), indicating extensive tissue distribution (concentrated in red blood cells, liver, lungs, and adipose tissue).
Oral: 50–60% (extensive first-pass metabolism)
Oral: ~100% (absolute bioavailability not formally determined, but absorption is complete with minimal first-pass metabolism; relative bioavailability is high based on AUC and clinical efficacy).
GFR 30-50 m L/min: maximum 1 tablet twice daily. GFR <30 m L/min: avoid use.
No dose adjustment required for mild to moderate renal impairment (Cr Cl ≥30 m L/min). Not recommended for severe renal impairment (Cr Cl <30 m L/min) due to lack of data.
Child-Pugh A: caution, reduce dose. Child-Pugh B: avoid. Child-Pugh C: contraindicated.
Contraindicated in Child-Pugh Class B or C. Use with caution in mild hepatic impairment (Child-Pugh Class A) with no dose adjustment.
Not recommended for pediatric use; safety in children under 12 years not established.
Safety and efficacy not established in pediatric patients (<18 years).
Start with 1 tablet once daily; monitor for hypotension and electrolyte imbalance. Reduce initial dose by 50%.
No specific dose adjustment; use with monitoring for renal function due to age-related decline and potential for increased adverse effects.
None
ARAKODA can cause hemolytic anemia in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency. G6PD testing must be performed before prescribing due to risk of hemolytic anemia.
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.
Hemolytic anemia in G6PD-deficient patients (contraindicated in G6PD deficiency without prior testing),Methemoglobinemia (rare, monitor for cyanosis and dyspnea),Psychiatric effects including anxiety, depression, and insomnia,Hepatotoxicity (rare, monitor liver function),Use in pregnancy: not recommended (risk of hemolysis in G6PD-deficient fetus),Lactation: avoid if breastfeeding infant is G6PD deficient
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)
G6PD deficiency (without confirmed normal G6PD activity),Known hypersensitivity to tafenoquine or any 8-aminoquinoline,Use in children <16 years (safety not established),Severe renal impairment (e GFR <30 m L/min),Lactation in infants with G6PD deficiency or unknown G6PD status
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.
Take with a fatty meal to increase absorption. No specific dietary restrictions. Avoid grapefruit juice as it may alter metabolism.
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.
FDA Pregnancy Category C. First trimester: animal studies show fetal harm; human data insufficient. Second/third trimester: risk of fetal growth restriction; consider risk-benefit.
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.
Excreted in human milk; M/P ratio unknown. Potential for adverse effects in infant; use caution, consider discontinuing breastfeeding.
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.
No established dose adjustments; pharmacokinetic changes in pregnancy may require monitoring drug levels and clinical response.
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.
ARAKODA (tafenoquine) is indicated for radical cure of Plasmodium vivax malaria. Assess G6PD status before prescribing; contraindicated in G6PD-deficient patients due to hemolytic anemia risk. Monitor for methemoglobinemia. Avoid use in pregnancy/lactation. Take with food to enhance absorption.
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.
Take with food to improve absorption.,You must be tested for G6PD deficiency before starting this medication.,Report any signs of anemia, dark urine, or yellowing of eyes/skin.,Avoid use during pregnancy or breastfeeding.,Do not drive if you experience dizziness or blurred vision.
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 ALDORIL 15 vs ARAKODA, answered by our medical review team.
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.. ARAKODA is a Antimalarial that works by ARAKODA (tafenoquine) is an 8-aminoquinoline antimalarial agent that inhibits the conversion of Plasmodium protozoa from liver stage to blood stage, thereby preventing relapses. Its exact mechanism may involve interference with electron transport or generation of reactive oxygen species.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between ALDORIL 15 and ARAKODA 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 ALDORIL 15 is: 1 tablet (hydrochlorothiazide 15 mg, methyldopa 250 mg) orally twice daily; increase as needed up to 2 tablets twice daily.. The standard adult dose of ARAKODA is: 400 mg orally once daily for 3 days, then 200 mg once daily for maintenance (up to 12 months).. 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 ALDORIL 15 and ARAKODA 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. 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: . ARAKODA is classified as Category C. FDA Pregnancy Category C. First trimester: animal studies show fetal harm; human data insufficient. Second/third trimester: risk of fetal growth restriction; consider risk-benefit.. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.