Comparative Pharmacology
Head-to-head clinical analysis: AZO GANTRISIN versus SULSTER.
Peer-Reviewed Evidence
Head-to-head clinical analysis: AZO GANTRISIN versus SULSTER.
AZO GANTRISIN vs SULSTER
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.
Sulster is a sulfonamide antibiotic that inhibits bacterial dihydropteroate synthase, blocking folate synthesis and thus bacterial DNA replication.
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.
2.5 mg orally twice daily.
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.
Terminal half-life 3.5-4.5 hours in normal renal function; prolonged to 10-15 hours with creatinine clearance <30 mL/min.
Renal: 70-100% (sulfamethoxazole and metabolites; 15-30% as unchanged drug; remainder as acetylated and glucuronide conjugates). Biliary/fecal: <3%.
Primarily renal (60-70% unchanged), with 20-30% as glucuronide conjugate; biliary/fecal <10%.
Category C
Category C
Sulfonamide Antibiotic
Sulfonamide Antibiotic