Comparative Pharmacology
Head-to-head clinical analysis: SULFATRIM versus SULFATRIM SS.
Peer-Reviewed Evidence
Head-to-head clinical analysis: SULFATRIM versus SULFATRIM SS.
SULFATRIM vs SULFATRIM-SS
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Sulfatrim is a combination of sulfamethoxazole, a dihydropteroate synthase inhibitor that blocks folate synthesis, and trimethoprim, a dihydrofolate reductase inhibitor that blocks reduction of dihydrofolate to tetrahydrofolate, resulting in sequential inhibition of bacterial folate metabolism.
Sulfamethoxazole inhibits bacterial dihydropteroate synthase, blocking folate synthesis. Trimethoprim inhibits bacterial dihydrofolate reductase, blocking reduction of dihydrofolate to tetrahydrofolate. Sequential blockade produces bactericidal synergy.
160 mg trimethoprim / 800 mg sulfamethoxazole (1 DS tablet) orally every 12 hours for 10-14 days.
1 double-strength tablet (160 mg trimethoprim / 800 mg sulfamethoxazole) orally every 12 hours for 10-14 days.
None Documented
None Documented
Sulfamethoxazole: 9-11 hours (prolonged in renal impairment, e.g., up to 30 hours in severe renal failure). Trimethoprim: 8-10 hours (prolonged in hepatic impairment).
SMX: 9-12 hours (increased in renal impairment); TMP: 8-11 hours (increased in renal impairment); both prolonged in elderly.
Renal (70-80% as unchanged sulfamethoxazole and N4-acetylated metabolite; 30-40% as unchanged trimethoprim), biliary/fecal (20-30% sulfamethoxazole; 10-20% trimethoprim)
Renal excretion of unchanged sulfamethoxazole (SMX) approximately 20%, trimethoprim (TMP) approximately 60%; biliary/fecal elimination minor (SMX <5%, TMP <10%).
Category C
Category C
Sulfonamide Antibiotic
Sulfonamide Antibiotic