Comparative Pharmacology
Head-to-head clinical analysis: AZO GANTRISIN versus SULFONAMIDES DUPLEX.
Peer-Reviewed Evidence
Head-to-head clinical analysis: AZO GANTRISIN versus SULFONAMIDES DUPLEX.
AZO GANTRISIN vs SULFONAMIDES DUPLEX
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.
Sulfonamides are competitive antagonists of para-aminobenzoic acid (PABA) and inhibit dihydropteroate synthase, blocking folate synthesis in susceptible bacteria.
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.
Oral: 500-1000 mg twice daily; maximum 2000 mg/day.
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: 7-12 hours in patients with normal renal function; prolonged to 24-50 hours in renal impairment (CrCl <30 mL/min) due to reduced elimination.
Renal: 70-100% (sulfamethoxazole and metabolites; 15-30% as unchanged drug; remainder as acetylated and glucuronide conjugates). Biliary/fecal: <3%.
Renal: 70-100% unchanged drug via glomerular filtration and tubular secretion; fecal/biliary: <5%.
Category C
Category C
Sulfonamide Antibiotic
Sulfonamide Antibiotic