Comparative Pharmacology
Head-to-head clinical analysis: TRIMETH SULFA versus UROPLUS SS.
Peer-Reviewed Evidence
Head-to-head clinical analysis: TRIMETH SULFA versus UROPLUS SS.
TRIMETH/SULFA vs UROPLUS SS
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Trimethoprim inhibits bacterial dihydrofolate reductase (DHFR), blocking conversion of dihydrofolate to tetrahydrofolate; sulfamethoxazole inhibits bacterial dihydropteroate synthase, blocking incorporation of para-aminobenzoic acid into folic acid. Sequential blockade of folate synthesis produces synergistic bactericidal effect.
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.
1 double-strength tablet (160 mg trimethoprim / 800 mg sulfamethoxazole) orally every 12 hours for 14 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
Trimethoprim: 8-11 hours; Sulfamethoxazole: 9-11 hours. Prolonged in renal impairment (up to 24-30 hours for both). Clinical context: Dosing interval is typically 12 hours in normal renal function; adjust in CrCl <15-30 mL/min.
Terminal elimination half-life is 18–24 hours, allowing once-daily dosing; steady-state achieved in 3–5 days.
Trimethoprim: 50-60% unchanged in urine; Sulfamethoxazole: 15-30% unchanged in urine, with acetylation and glucuronidation metabolites. Approximately 80-90% of dose recovered in urine within 72 hours; remainder via feces.
Renal: 70–80% as unchanged drug; fecal: 10–20% via biliary elimination; minimal hepatic metabolism.
Category C
Category C
Sulfonamide Antibiotic
Sulfonamide Antibiotic