Comparative Pharmacology
Head-to-head clinical analysis: MICROSUL versus SULFATRIM SS.
Head-to-head clinical analysis: MICROSUL versus SULFATRIM SS.
MICROSUL vs SULFATRIM-SS
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
MICROSUL inhibits bacterial dihydropteroate synthase, preventing folate synthesis, and also acts as a competitive antagonist of para-aminobenzoic acid (PABA).
Sulfamethoxazole inhibits bacterial dihydropteroate synthase, blocking folate synthesis. Trimethoprim inhibits bacterial dihydrofolate reductase, blocking reduction of dihydrofolate to tetrahydrofolate. Sequential blockade produces bactericidal synergy.
Adult: 160 mg/800 mg (trimethoprim/sulfamethoxazole) orally every 12 hours for 14 days; intravenous dosing: 8-10 mg/kg/day (as trimethoprim) divided every 6, 8, or 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: 24-36 hours; prolonged in renal impairment
SMX: 9-12 hours (increased in renal impairment); TMP: 8-11 hours (increased in renal impairment); both prolonged in elderly.
Renal: 70% unchanged; biliary/fecal: 30% as metabolites
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