Comparative Pharmacology
Head-to-head clinical analysis: SULFATRIM SS versus SULFONAMIDES DUPLEX.
Peer-Reviewed Evidence
Head-to-head clinical analysis: SULFATRIM SS versus SULFONAMIDES DUPLEX.
SULFATRIM-SS vs SULFONAMIDES DUPLEX
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Sulfamethoxazole inhibits bacterial dihydropteroate synthase, blocking folate synthesis. Trimethoprim inhibits bacterial dihydrofolate reductase, blocking reduction of dihydrofolate to tetrahydrofolate. Sequential blockade produces bactericidal synergy.
Sulfonamides are competitive antagonists of para-aminobenzoic acid (PABA) and inhibit dihydropteroate synthase, blocking folate synthesis in susceptible bacteria.
1 double-strength tablet (160 mg trimethoprim / 800 mg sulfamethoxazole) orally every 12 hours for 10-14 days.
Oral: 500-1000 mg twice daily; maximum 2000 mg/day.
None Documented
None Documented
SMX: 9-12 hours (increased in renal impairment); TMP: 8-11 hours (increased in renal impairment); both prolonged in elderly.
Terminal half-life: 7-12 hours in patients with normal renal function; prolonged to 24-50 hours in renal impairment (CrCl <30 mL/min) due to reduced elimination.
Renal excretion of unchanged sulfamethoxazole (SMX) approximately 20%, trimethoprim (TMP) approximately 60%; biliary/fecal elimination minor (SMX <5%, TMP <10%).
Renal: 70-100% unchanged drug via glomerular filtration and tubular secretion; fecal/biliary: <5%.
Category C
Category C
Sulfonamide Antibiotic
Sulfonamide Antibiotic