Comparative Pharmacology
Head-to-head clinical analysis: SULFAMETHOPRIM DS versus SULFATRIM DS.
Peer-Reviewed Evidence
Head-to-head clinical analysis: SULFAMETHOPRIM DS versus SULFATRIM DS.
SULFAMETHOPRIM-DS vs SULFATRIM-DS
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.
Sulfamethoxazole inhibits bacterial dihydropteroate synthase, blocking folate synthesis. Trimethoprim inhibits bacterial dihydrofolate reductase, inhibiting reduction of dihydrofolate to tetrahydrofolate. Sequential blockade of folate metabolism exerts bactericidal effect.
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.
One double-strength tablet (160 mg trimethoprim/800 mg sulfamethoxazole) orally every 12 hours.
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.
SMX: 9-11 hours (terminal); TMP: 8-10 hours; prolonged in renal impairment (creatinine clearance <30 mL/min: up to 20-30 hours for both).
Renal excretion of unchanged drug (50-70%) and metabolites (primarily N4-acetylated form, 15-30%); biliary/fecal excretion accounts for <5%.
Renal: 50-70% of total sulfamethoxazole (SMX) and 30% of trimethoprim (TMP) as unchanged drug via glomerular filtration and tubular secretion; 20-40% of SMX as N4-acetylated metabolite; biliary excretion accounts for <5%.
Category C
Category C
Sulfonamide Antibiotic
Sulfonamide Antibiotic