Comparative Pharmacology
Head-to-head clinical analysis: MALARONE PEDIATRIC versus PYRIMETHAMINE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: MALARONE PEDIATRIC versus PYRIMETHAMINE.
MALARONE PEDIATRIC vs PYRIMETHAMINE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
MALARONE PEDIATRIC is a fixed-dose combination of atovaquone and proguanil. Atovaquone selectively inhibits the mitochondrial electron transport chain of Plasmodium species at the cytochrome bc1 complex, collapsing mitochondrial membrane potential and disrupting pyrimidine synthesis. Proguanil is a prodrug converted to cycloguanil, which inhibits dihydrofolate reductase in the parasite, blocking DNA synthesis. The combination synergistically kills blood-stage schizonts and inhibits liver-stage hypnozoites of P. falciparum.
Pyrimethamine inhibits dihydrofolate reductase (DHFR) in the parasite, blocking the conversion of dihydrofolate to tetrahydrofolate, thereby inhibiting nucleic acid synthesis.
Adults: 250 mg atovaquone/100 mg proguanil orally once daily for 3 consecutive days for treatment; for prophylaxis, 250 mg/100 mg orally once daily starting 1-2 days before travel and continued 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
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
moderateNone Documented
Atovaquone: terminal half-life 1.5-3 days (range 2-3 days in adults, longer in children). Proguanil: terminal half-life 12-21 hours (parent drug) and 14-23 hours (cycloguanil). Clinically, atovaquone's long half-life supports single daily dosing.
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: >90% excreted unchanged in feces via biliary elimination; <1% renal. Proguanil: ~40-60% excreted renally as unchanged drug and active metabolite cycloguanil; ~30% fecal.
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."