Comparative Pharmacology
Head-to-head clinical analysis: SULFAMETHOPRIM versus SULFATRIM SS.
Peer-Reviewed Evidence
Head-to-head clinical analysis: SULFAMETHOPRIM versus SULFATRIM SS.
SULFAMETHOPRIM vs SULFATRIM-SS
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Sulfamethoprim is a combination of sulfamethoxazole and trimethoprim. Sulfamethoxazole inhibits bacterial dihydropteroate synthase, blocking folic acid synthesis; trimethoprim inhibits bacterial dihydrofolate reductase, also blocking folic acid synthesis. This sequential blockade produces bactericidal effects.
Sulfamethoxazole inhibits bacterial dihydropteroate synthase, blocking folate synthesis. Trimethoprim inhibits bacterial dihydrofolate reductase, blocking reduction of dihydrofolate to tetrahydrofolate. Sequential blockade produces bactericidal synergy.
Oral or intravenous: 800 mg sulfamethoxazole / 160 mg trimethoprim every 12 hours.
1 double-strength tablet (160 mg trimethoprim / 800 mg sulfamethoxazole) orally every 12 hours for 10-14 days.
None Documented
None Documented
Terminal elimination half-life: 8-12 hours in adults with normal renal function. Prolonged in renal impairment (up to 24-48 hours).
SMX: 9-12 hours (increased in renal impairment); TMP: 8-11 hours (increased in renal impairment); both prolonged in elderly.
Renal: 60-80% as unchanged drug via glomerular filtration and tubular secretion; biliary: 5-10%; fecal: <5%.
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