Comparative Pharmacology
Head-to-head clinical analysis: TRIMETHOPRIM SULFAMETHOXAZOLE versus UROPLUS SS.
Peer-Reviewed Evidence
Head-to-head clinical analysis: TRIMETHOPRIM SULFAMETHOXAZOLE versus UROPLUS SS.
Trimethoprim-Sulfamethoxazole vs UROPLUS SS
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Sulfamethoxazole inhibits dihydropteroate synthase, blocking para-aminobenzoic acid incorporation into dihydrofolate; trimethoprim inhibits dihydrofolate reductase, preventing tetrahydrofolate formation. Sequential blockade of folate synthesis.
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.
Oral: 160 mg TMP/800 mg SMX every 12 hours; IV: 8-10 mg/kg/day (based on TMP) in 2-4 divided doses
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
Trimethoprim: 8-10 hours (normal renal function); prolonged to 24-30 hours in severe renal impairment (CrCl <10 mL/min). Sulfamethoxazole: 9-11 hours; prolonged in renal failure. The combination retains a half-life of ~10-12 hours in healthy adults, requiring dose adjustment in renal impairment.
Terminal elimination half-life is 18–24 hours, allowing once-daily dosing; steady-state achieved in 3–5 days.
Trimethoprim: 50-60% excreted unchanged in urine via glomerular filtration and tubular secretion; 10-20% as metabolites. Sulfamethoxazole: 20-30% excreted unchanged in urine; 50-70% as N4-acetylated metabolite. Both undergo minimal biliary/fecal elimination (<5% total).
Renal: 70–80% as unchanged drug; fecal: 10–20% via biliary elimination; minimal hepatic metabolism.
Category C
Category C
Sulfonamide Antibiotic
Sulfonamide Antibiotic