Comparative Pharmacology
Head-to-head clinical analysis: SEPTRA versus TRIMETHOPRIM.
Peer-Reviewed Evidence
Head-to-head clinical analysis: SEPTRA versus TRIMETHOPRIM.
SEPTRA vs TRIMETHOPRIM
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
SEPTRA (trimethoprim/sulfamethoxazole) is a combination of two antifolate agents: sulfamethoxazole inhibits dihydropteroate synthase, blocking the conversion of PABA to dihydrofolic acid; trimethoprim inhibits dihydrofolate reductase, preventing the reduction of dihydrofolic acid to tetrahydrofolic acid. This sequential blockade disrupts bacterial folate synthesis and nucleic acid production.
Trimethoprim inhibits bacterial dihydrofolate reductase (DHFR), preventing the reduction of dihydrofolate to tetrahydrofolate, thereby inhibiting thymidine synthesis and bacterial DNA replication. It has bacteriostatic activity against susceptible organisms.
Trimethoprim-sulfamethoxazole (TMP-SMX) 160 mg/800 mg (double strength) orally every 12 hours; for severe infections, intravenous dosing: 8-10 mg/kg/day (TMP component) divided every 6, 8, or 12 hours.
Adult: 100 mg orally twice daily or 200 mg once daily for uncomplicated UTI; for severe infections, up to 20 mg/kg/day in divided doses. IV: 10-20 mg/kg/day divided every 6-12 hours.
None Documented
None Documented
Clinical Note
moderateTrimethoprim + Teriflunomide
"The metabolism of Teriflunomide can be decreased when combined with Trimethoprim."
Clinical Note
moderateTrimethoprim + Sulfisoxazole
"The metabolism of Sulfisoxazole can be decreased when combined with Trimethoprim."
Clinical Note
moderateTrimethoprim + Cyclosporine
"The metabolism of Cyclosporine can be decreased when combined with Trimethoprim."
Clinical Note
moderateTrimethoprim + Fluconazole
Sulfamethoxazole: 9-12 hours (normal renal function); Trimethoprim: 8-11 hours (normal renal function). In severe renal impairment (CrCl <15 mL/min), half-life prolongs significantly (up to 24-30 hours for sulfamethoxazole, 20-30 hours for trimethoprim).
Terminal elimination half-life is 8-12 hours in adults with normal renal function; prolonged to 20-40 hours in severe renal impairment (CrCl <15 mL/min).
Renal excretion of unchanged sulfamethoxazole (~20%) and trimethoprim (~50-60%) with additional hepatic metabolism (acetylation, glucuronidation) of sulfamethoxazole; total renal elimination accounts for ~80-90% of the dose (sulfamethoxazole 30% parent, 40% metabolites; trimethoprim 60-80% parent, remainder as metabolites). Biliary/fecal <5%.
Renal excretion: approximately 50-60% of the dose is excreted unchanged in urine via glomerular filtration and tubular secretion; about 10-20% as metabolites (conjugated and oxidized forms); biliary/fecal excretion accounts for less than 10%.
Category C
Category D/X
Antibiotic
Antibiotic
"The metabolism of Fluconazole can be decreased when combined with Trimethoprim."