Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
FANSIDAR vs ARAKODA
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Fansidar combines sulfadoxine, a sulfonamide dihydrofolate reductase inhibitor, and pyrimethamine, a dihydrofolate reductase inhibitor, synergistically inhibiting folate synthesis in Plasmodium species, leading to nucleic acid synthesis inhibition and parasite death.
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.
Treatment of chloroquine-resistant Plasmodium falciparum malaria (FDA-approved),Prevention of malaria in travelers to regions with chloroquine-resistant P. falciparum (off-label)
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
For acute uncomplicated malaria: 3 tablets (25 mg pyrimethamine + 500 mg sulfadoxine per tablet) orally as a single dose on Day 0 and Day 1 (total 6 tablets); alternatively, 3 tablets as a single dose. For severe malaria: 3 tablets orally as a single dose, repeated at weekly intervals if necessary.
400 mg orally once daily for 3 days, then 200 mg once daily for maintenance (up to 12 months).
Sulfadoxine: 100-200 hours; pyrimethamine: 80-100 hours; clinical context: unusual for antimalarials, allows single-dose therapy for uncomplicated P. falciparum
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.
Sulfadoxine is primarily metabolized by N-acetyltransferase (NAT) to N-acetylsulfadoxine; pyrimethamine is metabolized by hepatic microsomal enzymes, including CYP2C9 and CYP3A4. Both are excreted renally.
Primarily metabolized by CYP2D6 and monoamine oxidase (MAO). Tafenoquine undergoes extensive metabolism including N-dealkylation and oxidation.
Renal: sulfadoxine 80% (unchanged), pyrimethamine 20-40% (unchanged); fecal: sulfadoxine <5%, pyrimethamine <5%
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).
Sulfadoxine: 90-95% bound to albumin; pyrimethamine: 70-80% bound to albumin and globulins
~99.5% bound to human serum albumin (HSA); binding is high and saturable, with unbound fraction slightly increasing at high concentrations.
Sulfadoxine: 1.5-2.0 L/kg (distributes widely including CSF); pyrimethamine: 2.0-3.0 L/kg (extensive tissue distribution)
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: sulfadoxine >85%, pyrimethamine >90%; IM: essentially 100%
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).
Cr Cl 10-50 m L/min: no adjustment recommended. Cr Cl <10 m L/min: contraindicated.
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 Class A: no adjustment. Child-Pugh Class B or C: avoid use due to risk of hepatotoxicity and accumulation.
Contraindicated in Child-Pugh Class B or C. Use with caution in mild hepatic impairment (Child-Pugh Class A) with no dose adjustment.
Weight-based single dose: 5-10 kg: 1/4 tablet; 11-20 kg: 1/2 tablet; 21-30 kg: 3/4 tablet; 31-45 kg: 1 tablet; >45 kg: 2 tablets. Administer orally, repeat on Day 1 if indicated.
Safety and efficacy not established in pediatric patients (<18 years).
No specific dose adjustment recommended, but monitor renal function closely due to age-related decline; sulfadoxine-pyrimethamine is generally well-tolerated in elderly, but caution with hepatic or renal impairment.
No specific dose adjustment; use with monitoring for renal function due to age-related decline and potential for increased adverse effects.
Fatalities due to severe adverse reactions, including Stevens-Johnson syndrome, toxic epidermal necrolysis, hepatic necrosis, agranulocytosis, aplastic anemia, and other blood dyscrasias have been reported. Fansidar should not be used for malaria prophylaxis due to the risk of severe skin reactions.
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.
Severe cutaneous adverse reactions (Stevens-Johnson syndrome, toxic epidermal necrolysis), hematologic toxicity (agranulocytosis, aplastic anemia), hepatic toxicity, hypersensitivity reactions, and photosensitivity. Monitor for skin reactions, blood dyscrasias, and hepatic function.
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
Hypersensitivity to sulfadoxine, pyrimethamine, or any sulfonamide; history of severe cutaneous adverse reactions due to sulfonamides; folate deficiency; megaloblastic anemia; infants <2 months of age (due to risk of kernicterus); pregnancy (especially first trimester) and lactation (due to risk of kernicterus and folate antagonism).
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 alcohol during treatment to reduce hepatotoxicity risk. High-fat meals may slightly increase pyrimethamine absorption; maintain consistent diet. Do not take with folic acid supplements as they may antagonize the drug's antifolate effect. Avoid excessive caffeine consumption; pyrimethamine may increase caffeine levels.
Take with a fatty meal to increase absorption. No specific dietary restrictions. Avoid grapefruit juice as it may alter metabolism.
Pregnancy Category C. First trimester: Contraindicated due to sulfadoxine-pyrimethamine's antifolate activity, associated with neural tube defects and major congenital malformations (anencephaly, cleft palate) based on animal studies and human case reports. Second and third trimesters: Use only if benefit outweighs risk; no adequate human studies show fetal harm in later trimesters, but theoretical risk of kernicterus in neonate due to sulfadoxine displacement of bilirubin, especially if near term.
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.
Both components are excreted into breast milk. Sulfadoxine: M/P ratio ~0.5; pyrimethamine: M/P ratio ~0.5. Concentrations in milk are low (<50% maternal plasma levels). Theoretical risk of kernicterus in jaundiced, G6PD-deficient, or ill neonates. Avoid in nursing mothers with infants at risk for hemolytic anemia. Consider alternative antimalarials during breastfeeding.
Excreted in human milk; M/P ratio unknown. Potential for adverse effects in infant; use caution, consider discontinuing breastfeeding.
No dose adjustment recommended for Fansidar in pregnancy. However, pharmacokinetic changes (increased volume of distribution, reduced plasma protein binding) may slightly lower peak concentrations, but clinical efficacy is maintained. Avoid use in first trimester; if necessary in second/third trimester, use standard dose (sulfadoxine 500 mg + pyrimethamine 25 mg) as single dose for malaria treatment or weekly prophylaxis at same dose.
No established dose adjustments; pharmacokinetic changes in pregnancy may require monitoring drug levels and clinical response.
Fansidar (sulfadoxine/pyrimethamine) is a fixed-dose combination antifolate used for malaria prophylaxis and treatment. Due to severe adverse reactions (Stevens-Johnson syndrome, toxic epidermal necrolysis), it is no longer recommended for prophylaxis in travelers; reserved for chloroquine-resistant Plasmodium falciparum malaria when other agents are unavailable. Administer with food to reduce GI upset. Monitor for hypersensitivity, especially in patients with sulfonamide allergy. Not effective against P. vivax or P. ovale. Consider G6PD deficiency screening before use.
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.
Take with a full glass of water and with food to prevent stomach upset.,Complete the full course even if symptoms improve.,Seek immediate medical attention for rash, blisters, mouth sores, or fever—these could signal a severe skin reaction.,Avoid prolonged sun exposure and use sunscreen; photosensitivity may occur.,Inform your doctor of all medications, especially methotrexate, warfarin, or antiepileptics.,Not recommended for pregnant women or nursing mothers unless specifically advised by a physician.,Do not take if you have a sulfa allergy or history of folic acid deficiency anemia.,Store at room temperature away from moisture and heat.
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 FANSIDAR vs ARAKODA, answered by our medical review team.
FANSIDAR is a Antimalarial that works by Fansidar combines sulfadoxine, a sulfonamide dihydrofolate reductase inhibitor, and pyrimethamine, a dihydrofolate reductase inhibitor, synergistically inhibiting folate synthesis in Plasmodium species, leading to nucleic acid synthesis inhibition and parasite death.. 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 FANSIDAR and ARAKODA depend on the specific clinical indication. These are both Antimalarial agents and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of FANSIDAR is: For acute uncomplicated malaria: 3 tablets (25 mg pyrimethamine + 500 mg sulfadoxine per tablet) orally as a single dose on Day 0 and Day 1 (total 6 tablets); alternatively, 3 tablets as a single dose. For severe malaria: 3 tablets orally as a single dose, repeated at weekly intervals if necessary.. 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 FANSIDAR 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. FANSIDAR is classified as Category C. Pregnancy Category C. First trimester: Contraindicated due to sulfadoxine-pyrimethamine's antifolate activity, associated with neural tube defects and major congenital malformation. 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.