Comparative Pharmacology
Head-to-head clinical analysis: PRIMAQUINE versus PYRIMETHAMINE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: PRIMAQUINE versus PYRIMETHAMINE.
PRIMAQUINE vs PYRIMETHAMINE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Antimalarial agent that eliminates exoerythrocytic forms (hypnozoites) of Plasmodium vivax and P. ovale; also active against gametocytes. Mechanism involves generation of reactive oxygen species via redox cycling, disrupting parasite mitochondrial function.
Pyrimethamine inhibits dihydrofolate reductase (DHFR) in the parasite, blocking the conversion of dihydrofolate to tetrahydrofolate, thereby inhibiting nucleic acid synthesis.
15 mg (base) orally once daily for 14 days for radical cure of P. vivax and P. ovale; 30 mg (base) orally once daily for 7 days for terminal prophylaxis.
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
moderatePrimaquine + Norfloxacin
"Primaquine may increase the QTc-prolonging activities of Norfloxacin."
Clinical Note
moderatePrimaquine + Haloperidol
"Primaquine may increase the QTc-prolonging activities of Haloperidol."
Clinical Note
moderatePrimaquine + Ibandronate
"Primaquine may increase the QTc-prolonging activities of Ibandronate."
Clinical Note
moderatePrimaquine + Tenofovir disoproxil
"The metabolism of Tenofovir disoproxil can be decreased when combined with Primaquine."
Terminal elimination half-life of approximately 4-7 hours; in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency, half-life may be prolonged due to accumulation in erythrocytes
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 (60-65% as unchanged drug and metabolites); small amounts in feces (<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 D/X
Category D/X
Antimalarial
Antimalarial / Antiprotozoal