Comparative Pharmacology
Head-to-head clinical analysis: MEPRON versus PYRIMETHAMINE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: MEPRON versus PYRIMETHAMINE.
MEPRON vs PYRIMETHAMINE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
It is a hydroxynaphthoquinone that selectively inhibits mitochondrial electron transport chain in Plasmodium species, specifically at the cytochrome bc1 complex (Complex III), leading to collapse of mitochondrial membrane potential and inhibition of pyrimidine synthesis.
Pyrimethamine inhibits dihydrofolate reductase (DHFR) in the parasite, blocking the conversion of dihydrofolate to tetrahydrofolate, thereby inhibiting nucleic acid synthesis.
750 mg orally twice daily with food for 21 days for treatment of mild-to-moderate Pneumocystis jirovecii pneumonia. For prophylaxis: 1500 mg orally once daily with food.
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
moderateMean terminal elimination half-life is 2.2-3.2 days (approximately 53-77 hours) in adults; prolonged in hepatic impairment (up to 22 days) and in elderly (up to 5 days).
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.
Primarily fecal (87-94%) via bile; renal excretion accounts for <1% as unchanged drug. A minor metabolite, atovaquone glucuronide, is excreted in urine.
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 C
Category D/X
Antiprotozoal
Antimalarial / Antiprotozoal
Cyclophosphamide + Pyrimethamine
"The metabolism of Pyrimethamine can be decreased when combined with Cyclophosphamide."