Comparative Pharmacology
Head-to-head clinical analysis: AZO GANTRISIN versus UROPLUS SS.
Peer-Reviewed Evidence
Head-to-head clinical analysis: AZO GANTRISIN versus UROPLUS SS.
AZO GANTRISIN vs UROPLUS SS
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.
Uroplus SS contains sulfamethoxazole and trimethoprim. Sulfamethoxazole inhibits bacterial dihydrofolic acid synthesis by competing with para-aminobenzoic acid (PABA) for dihydropteroate synthase. Trimethoprim inhibits bacterial dihydrofolate reductase, blocking reduction of dihydrofolate to tetrahydrofolate. The sequential blockade of folic acid metabolism produces bactericidal activity.
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.
4 grams orally once daily as a single dose or in divided doses for 10 to 14 days for urinary tract infections.
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 elimination half-life is 18–24 hours, allowing once-daily dosing; steady-state achieved in 3–5 days.
Renal: 70-100% (sulfamethoxazole and metabolites; 15-30% as unchanged drug; remainder as acetylated and glucuronide conjugates). Biliary/fecal: <3%.
Renal: 70–80% as unchanged drug; fecal: 10–20% via biliary elimination; minimal hepatic metabolism.
Category C
Category C
Sulfonamide Antibiotic
Sulfonamide Antibiotic