Comparative Pharmacology
Head-to-head clinical analysis: KRINTAFEL versus PYRIMETHAMINE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: KRINTAFEL versus PYRIMETHAMINE.
KRINTAFEL vs PYRIMETHAMINE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
KRINTAFEL (tafenoquine) is an 8-aminoquinoline antimalarial that inhibits parasite growth by interfering with the electron transport chain in the mitochondria of Plasmodium species. It is active against both the erythrocytic and exoerythrocytic stages, including hypnozoites of P. vivax.
Pyrimethamine inhibits dihydrofolate reductase (DHFR) in the parasite, blocking the conversion of dihydrofolate to tetrahydrofolate, thereby inhibiting nucleic acid synthesis.
Adults: 200 mg orally as a single dose.
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
moderateTerminal elimination half-life is approximately 5-7 days in healthy subjects. Due to accumulation, steady state is achieved after 4-5 weeks of weekly dosing. In patients with renal impairment, half-life may be prolonged.
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 renal; approximately 70-80% of administered dose is excreted unchanged in urine via glomerular filtration and active tubular secretion. Fecal excretion accounts for less than 5%.
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."