Comparative Pharmacology
Head-to-head clinical analysis: SULFAMETHOPRIM DS versus SULFATRIM.
Peer-Reviewed Evidence
Head-to-head clinical analysis: SULFAMETHOPRIM DS versus SULFATRIM.
SULFAMETHOPRIM-DS vs SULFATRIM
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.
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.
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.
160 mg trimethoprim / 800 mg sulfamethoxazole (1 DS tablet) orally every 12 hours for 10-14 days.
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.
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).
Renal excretion of unchanged drug (50-70%) and metabolites (primarily N4-acetylated form, 15-30%); biliary/fecal excretion accounts for <5%.
Renal (70-80% as unchanged sulfamethoxazole and N4-acetylated metabolite; 30-40% as unchanged trimethoprim), biliary/fecal (20-30% sulfamethoxazole; 10-20% trimethoprim)
Category C
Category C
Sulfonamide Antibiotic
Sulfonamide Antibiotic