Comparative Pharmacology
Head-to-head clinical analysis: AZO GANTRISIN versus MICROSUL.
Peer-Reviewed Evidence
Head-to-head clinical analysis: AZO GANTRISIN versus MICROSUL.
AZO GANTRISIN vs MICROSUL
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.
MICROSUL inhibits bacterial dihydropteroate synthase, preventing folate synthesis, and also acts as a competitive antagonist of para-aminobenzoic acid (PABA).
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.
Adult: 160 mg/800 mg (trimethoprim/sulfamethoxazole) orally every 12 hours for 14 days; intravenous dosing: 8-10 mg/kg/day (as trimethoprim) divided every 6, 8, or 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.
Terminal elimination half-life: 24-36 hours; prolonged in renal impairment
Renal: 70-100% (sulfamethoxazole and metabolites; 15-30% as unchanged drug; remainder as acetylated and glucuronide conjugates). Biliary/fecal: <3%.
Renal: 70% unchanged; biliary/fecal: 30% as metabolites
Category C
Category C
Sulfonamide Antibiotic
Sulfonamide Antibiotic