Comparative Pharmacology
Head-to-head clinical analysis: MALARONE versus PYRIMETHAMINE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: MALARONE versus PYRIMETHAMINE.
MALARONE vs PYRIMETHAMINE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Atovaquone is a selective inhibitor of the mitochondrial electron transport chain at the cytochrome bc1 complex (Complex III), disrupting pyrimidine synthesis and ATP generation in Plasmodium species. Proguanil, via its metabolite cycloguanil, inhibits dihydrofolate reductase (DHFR), blocking DNA synthesis. Synergistic activity against erythrocytic and exoerythrocytic stages.
Pyrimethamine inhibits dihydrofolate reductase (DHFR) in the parasite, blocking the conversion of dihydrofolate to tetrahydrofolate, thereby inhibiting nucleic acid synthesis.
For malaria treatment: 4 tablets (each containing atovaquone 250 mg/proguanil 100 mg) orally once daily for 3 consecutive days. For malaria prophylaxis: 1 tablet (atovaquone 250 mg/proguanil 100 mg) orally once daily starting 1-2 days before travel, continued during travel and for 7 days after leaving endemic area.
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
moderateAtovaquone: 50-70 hours (mean ~60 h); proguanil: 12-21 hours (mean ~16 h); cycloguanil: 10-16 hours. Long half-life of atovaquone allows single-dose treatment, but may delay parasite clearance.
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.
Atovaquone: 94% excreted unchanged in feces via biliary elimination, 6% in urine. Proguanil: 40-60% excreted unchanged in urine; cycloguanil (active metabolite) and proguanil metabolites also cleared renally.
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
Antimalarial
Antimalarial / Antiprotozoal
Cyclophosphamide + Pyrimethamine
"The metabolism of Pyrimethamine can be decreased when combined with Cyclophosphamide."