Comparative Pharmacology
Head-to-head clinical analysis: MEFLOQUINE HYDROCHLORIDE versus PYRIMETHAMINE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: MEFLOQUINE HYDROCHLORIDE versus PYRIMETHAMINE.
MEFLOQUINE HYDROCHLORIDE vs PYRIMETHAMINE
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 (DHFR) in the parasite, blocking the conversion of dihydrofolate to tetrahydrofolate, thereby inhibiting nucleic acid synthesis.
250 mg (1 tablet) orally once weekly for prophylaxis; 1250 mg (5 tablets) as a single oral dose for treatment of uncomplicated malaria.
For toxoplasmosis: 200 mg orally once, then 50-75 mg orally once daily for 4-6 weeks, plus sulfadiazine and folinic acid. For malaria prophylaxis: 25 mg orally once weekly.
None Documented
None Documented
Clinical Note
moderatePyrimethamine + Fesoterodine
"The serum concentration of the active metabolites of Fesoterodine can be increased when Fesoterodine is used in combination with Pyrimethamine."
Clinical Note
moderatePyrimethamine + Artemether
"The risk or severity of QTc prolongation can be increased when Pyrimethamine is combined with Artemether."
Clinical Note
moderatePyrimethamine + Lumefantrine
"The risk or severity of QTc prolongation can be increased when Pyrimethamine is combined with Lumefantrine."
Clinical Note
moderate~2-4 weeks (terminal half-life); clinical context: long half-life allows weekly dosing for prophylaxis, but accumulation can occur with repeated doses.
Terminal elimination half-life is approximately 96 hours (range 80-123 hours) in adults with normal renal function; prolonged in renal impairment (up to 200 hours). This long half-life supports weekly dosing regimens.
~83% (fecal/biliary), ~9% (renal unchanged), ~2.5% (renal as metabolite).
Primarily renal (approximately 30% unchanged and 20-30% as metabolites); additional biliary/fecal elimination (20-30% as metabolites). Total urinary excretion of parent drug and metabolites accounts for 60-80% of dose.
Category A/B
Category D/X
Antimalarial
Antimalarial / Antiprotozoal
Cyclophosphamide + Pyrimethamine
"The metabolism of Pyrimethamine can be decreased when combined with Cyclophosphamide."