Comparative Pharmacology
Head-to-head clinical analysis: FANSIDAR versus HALFAN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: FANSIDAR versus HALFAN.
FANSIDAR vs HALFAN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
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.
HALFAN (halofantrine) is an antimalarial agent that acts as a blood schizonticide. It is thought to inhibit the polymerization of heme into hemozoin, leading to toxic accumulation of free heme within the parasite's food vacuole. It may also interfere with nucleic acid synthesis.
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.
Adults: 500 mg orally once daily.
None Documented
None Documented
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 is 10-18 hours (mean 14 hours) in healthy adults, allowing twice-daily dosing.
Renal: sulfadoxine 80% (unchanged), pyrimethamine 20-40% (unchanged); fecal: sulfadoxine <5%, pyrimethamine <5%
Primarily hepatic metabolism; renal excretion of metabolites accounts for <10% unchanged drug; biliary/fecal elimination of metabolites approximately 20-30%.
Category C
Category C
Antimalarial
Antimalarial