Comparative Pharmacology
Head-to-head clinical analysis: PRIMAQUINE versus PYRIMETHAMINE SULFADOXINE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: PRIMAQUINE versus PYRIMETHAMINE SULFADOXINE.
PRIMAQUINE vs Pyrimethamine-Sulfadoxine
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, blocking tetrahydrofolate synthesis. Sulfadoxine inhibits dihydropteroate synthase, blocking folate synthesis. Sequential blockade of folate metabolism.
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.
Pyrimethamine 25 mg plus sulfadoxine 500 mg per tablet; typical adult dose for acute uncomplicated malaria is 3 tablets (pyrimethamine 75 mg, sulfadoxine 1500 mg) orally as a single dose. For toxoplasmosis in immunocompromised patients: loading dose pyrimethamine 200 mg orally once, then pyrimethamine 50-75 mg orally once daily plus sulfadoxine 1000-1500 mg orally once daily (dosing based on sulfadoxine component) for 4-6 weeks, then reduce to half.
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
Pyrimethamine: ~80-120 hours; Sulfadoxine: ~100-200 hours. Long half-lives allow single-dose therapy for malaria.
Primarily renal (60-65% as unchanged drug and metabolites); small amounts in feces (<5%)
Renal: ~60% unchanged sulfadoxine, ~5% unchanged pyrimethamine; fecal: ~10% pyrimethamine. Biliary excretion minimal.
Category D/X
Category C
Antimalarial
Antimalarial