Comparative Pharmacology
Head-to-head clinical analysis: SULFAMETHOPRIM DS versus SULTRIN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: SULFAMETHOPRIM DS versus SULTRIN.
SULFAMETHOPRIM-DS vs SULTRIN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Sulfamethoprim-DS is a combination of sulfamethoxazole, a dihydropteroate synthase inhibitor, and trimethoprim, a dihydrofolate reductase inhibitor. The sequential inhibition of folate synthesis leads to bactericidal activity.
Sultrin (sulfanilamide, sulfathiazole, sulfacetamide) is a triple sulfonamide combination that acts as a bacteriostatic agent. It inhibits bacterial folic acid synthesis by competing with para-aminobenzoic acid (PABA) for the active site of dihydropteroate synthase, thereby blocking the conversion of PABA to dihydrofolic acid. This disrupts nucleic acid synthesis in susceptible bacteria.
Sulfamethoprim-DS (trimethoprim 160 mg-sulfamethoxazole 800 mg) orally every 12 hours for 10-14 days for uncomplicated UTI; for Pneumocystis jirovecii pneumonia: 3-5 mg/kg/day (based on TMP) orally or IV divided every 6-8 hours for 21 days.
Intravaginal administration: one applicatorful (approximately 5 g) of Sultrin Triple Sulfa Cream (containing sulfathiazole, sulfacetamide, and sulfabenzamide) intravaginally once or twice daily for 4 to 7 days. Oral: Not applicable.
None Documented
None Documented
Terminal elimination half-life of sulfamethoxazole is 9-11 hours (prolonged to 20-50 hours in severe renal impairment). Clinically, this supports twice-daily dosing in normal renal function; dose adjustment required for CrCl <30 mL/min.
Terminal half-life 8-12 hours; requires dose adjustment in renal impairment (CrCl <30 mL/min)
Renal excretion of unchanged drug (50-70%) and metabolites (primarily N4-acetylated form, 15-30%); biliary/fecal excretion accounts for <5%.
Renal: ~70% unchanged; biliary/fecal: ~30% as metabolites
Category C
Category C
Sulfonamide Antibiotic
Sulfonamide Antibiotic