Comparative Pharmacology
Head-to-head clinical analysis: FANSIDAR versus PLAQUENIL.
Peer-Reviewed Evidence
Head-to-head clinical analysis: FANSIDAR versus PLAQUENIL.
FANSIDAR vs PLAQUENIL
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.
Antimalarial and immunosuppressant; inhibits heme polymerase in Plasmodium, preventing conversion of toxic heme to hemozoin; also inhibits lysosomal function, antigen presentation, and cytokine production (e.g., IL-1, TNF-alpha) in autoimmune diseases.
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 (310 mg base) orally daily, or 400 mg/day in divided doses; maintenance: 200-400 mg/day
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: 32-50 days (range 22-124 days) due to extensive tissue distribution and slow release from melanin-rich tissues; requires long-term dosing to achieve steady state (3-6 months).
Renal: sulfadoxine 80% (unchanged), pyrimethamine 20-40% (unchanged); fecal: sulfadoxine <5%, pyrimethamine <5%
Renal (50-70% unchanged), fecal (20-30% as metabolites), minor biliary.
Category C
Category C
Antimalarial
Antimalarial