Comparative Pharmacology
Head-to-head clinical analysis: PYRIMETHAMINE versus QUININE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: PYRIMETHAMINE versus QUININE.
PYRIMETHAMINE vs Quinine
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Pyrimethamine inhibits dihydrofolate reductase (DHFR) in the parasite, blocking the conversion of dihydrofolate to tetrahydrofolate, thereby inhibiting nucleic acid synthesis.
Quinine is a cinchona alkaloid that acts as a blood schizonticide against Plasmodium falciparum. It inhibits heme polymerase, leading to accumulation of toxic heme, and disrupts parasite membrane integrity. It also has mild analgesic and antipyretic properties.
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.
Adults: 648 mg (2 capsules) orally every 8 hours for 7 days for uncomplicated chloroquine-resistant malaria, typically used in combination with other antimalarials.
MODERATE Risk
MODERATE Risk
Clinical Note
moderateQuinine + Gatifloxacin
"Quinine may increase the hypoglycemic activities of Gatifloxacin."
Clinical Note
moderateQuinine + Rosoxacin
"Quinine may increase the hypoglycemic activities of Rosoxacin."
Clinical Note
moderateQuinine + Levofloxacin
"Quinine may increase the hypoglycemic activities of Levofloxacin."
Clinical Note
moderateQuinine + Trovafloxacin
"Quinine may increase the hypoglycemic activities of Trovafloxacin."
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.
Terminal elimination half-life: 18 hours (range 8–21 h) in healthy adults; prolonged to 26–44 h in severe malaria or hepatic impairment.
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.
Renal: ~20% unchanged; Hepatic metabolism (CYP3A4) to inactive metabolites, excreted in urine and feces. Total renal elimination of parent and metabolites ~80%.
Category D/X
Category C
Antimalarial / Antiprotozoal
Antimalarial