Comparative Pharmacology
Head-to-head clinical analysis: SULFACETAMIDE SODIUM versus SULFATRIM SS.
Peer-Reviewed Evidence
Head-to-head clinical analysis: SULFACETAMIDE SODIUM versus SULFATRIM SS.
SULFACETAMIDE SODIUM vs SULFATRIM-SS
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Competitively inhibits dihydropteroate synthase, blocking folic acid synthesis in susceptible bacteria.
Sulfamethoxazole inhibits bacterial dihydropteroate synthase, blocking folate synthesis. Trimethoprim inhibits bacterial dihydrofolate reductase, blocking reduction of dihydrofolate to tetrahydrofolate. Sequential blockade produces bactericidal synergy.
1-2 drops of 10-30% solution into the conjunctival sac every 2-3 hours initially, tapering as infection resolves. Ointment: 0.5-inch ribbon into conjunctival sac every 3-4 hours and at bedtime.
1 double-strength tablet (160 mg trimethoprim / 800 mg sulfamethoxazole) orally every 12 hours for 10-14 days.
None Documented
None Documented
7-12.8 hours (prolonged in renal impairment; requires dosing adjustment in CrCl <50 mL/min).
SMX: 9-12 hours (increased in renal impairment); TMP: 8-11 hours (increased in renal impairment); both prolonged in elderly.
Renal: 85-95% unchanged via glomerular filtration and tubular secretion. Biliary/fecal: <5%.
Renal excretion of unchanged sulfamethoxazole (SMX) approximately 20%, trimethoprim (TMP) approximately 60%; biliary/fecal elimination minor (SMX <5%, TMP <10%).
Category A/B
Category C
Sulfonamide Antibiotic
Sulfonamide Antibiotic