Comparative Pharmacology
Head-to-head clinical analysis: AZO GANTRISIN versus SULFATRIM DS.
Peer-Reviewed Evidence
Head-to-head clinical analysis: AZO GANTRISIN versus SULFATRIM DS.
AZO GANTRISIN vs SULFATRIM-DS
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Sulfamethoxazole is a competitive inhibitor of dihydropteroate synthase, blocking bacterial folic acid synthesis. Phenazopyridine is an azo dye with local analgesic effects on urinary tract mucosa.
Sulfamethoxazole inhibits bacterial dihydropteroate synthase, blocking folate synthesis. Trimethoprim inhibits bacterial dihydrofolate reductase, inhibiting reduction of dihydrofolate to tetrahydrofolate. Sequential blockade of folate metabolism exerts bactericidal effect.
AZO GANTRISIN (phenazopyridine 100 mg / sulfisoxazole 500 mg): 2 tablets orally 4 times daily for 2 days, then 1 tablet 4 times daily for up to 5 days.
One double-strength tablet (160 mg trimethoprim/800 mg sulfamethoxazole) orally every 12 hours.
None Documented
None Documented
Sulfamethoxazole: 9-12 hours (adults with normal renal function), prolonged to 20-50 hours in renal impairment; trimethoprim component: 8-11 hours. Clinical context: dosing interval adjusted based on CrCl.
SMX: 9-11 hours (terminal); TMP: 8-10 hours; prolonged in renal impairment (creatinine clearance <30 mL/min: up to 20-30 hours for both).
Renal: 70-100% (sulfamethoxazole and metabolites; 15-30% as unchanged drug; remainder as acetylated and glucuronide conjugates). Biliary/fecal: <3%.
Renal: 50-70% of total sulfamethoxazole (SMX) and 30% of trimethoprim (TMP) as unchanged drug via glomerular filtration and tubular secretion; 20-40% of SMX as N4-acetylated metabolite; biliary excretion accounts for <5%.
Category C
Category C
Sulfonamide Antibiotic
Sulfonamide Antibiotic