Comparative Pharmacology
Head-to-head clinical analysis: MEFLOQUINE HYDROCHLORIDE versus PYRIMETHAMINE SULFADOXINE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: MEFLOQUINE HYDROCHLORIDE versus PYRIMETHAMINE SULFADOXINE.
MEFLOQUINE HYDROCHLORIDE vs Pyrimethamine-Sulfadoxine
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Mefloquine is a quinoline antimalarial agent that acts as a blood schizontocide. Its exact mechanism is unknown but is thought to involve forming toxic heme complexes or inhibiting heme polymerase, leading to parasite death.
Pyrimethamine inhibits dihydrofolate reductase, blocking tetrahydrofolate synthesis. Sulfadoxine inhibits dihydropteroate synthase, blocking folate synthesis. Sequential blockade of folate metabolism.
250 mg (1 tablet) orally once weekly for prophylaxis; 1250 mg (5 tablets) as a single oral dose for treatment of uncomplicated malaria.
Pyrimethamine 25 mg plus sulfadoxine 500 mg per tablet; typical adult dose for acute uncomplicated malaria is 3 tablets (pyrimethamine 75 mg, sulfadoxine 1500 mg) orally as a single dose. For toxoplasmosis in immunocompromised patients: loading dose pyrimethamine 200 mg orally once, then pyrimethamine 50-75 mg orally once daily plus sulfadoxine 1000-1500 mg orally once daily (dosing based on sulfadoxine component) for 4-6 weeks, then reduce to half.
None Documented
None Documented
~2-4 weeks (terminal half-life); clinical context: long half-life allows weekly dosing for prophylaxis, but accumulation can occur with repeated doses.
Pyrimethamine: ~80-120 hours; Sulfadoxine: ~100-200 hours. Long half-lives allow single-dose therapy for malaria.
~83% (fecal/biliary), ~9% (renal unchanged), ~2.5% (renal as metabolite).
Renal: ~60% unchanged sulfadoxine, ~5% unchanged pyrimethamine; fecal: ~10% pyrimethamine. Biliary excretion minimal.
Category A/B
Category C
Antimalarial
Antimalarial