Comparative Pharmacology
Head-to-head clinical analysis: ILOSONE SULFA versus SULFATRIM SS.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ILOSONE SULFA versus SULFATRIM SS.
ILOSONE SULFA vs SULFATRIM-SS
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Ilosone (erythromycin) is a macrolide antibiotic that inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit. Sulfa (sulfisoxazole) is a sulfonamide that inhibits dihydropteroate synthase, blocking folate synthesis. The combination provides synergistic bacteriostatic activity.
Sulfamethoxazole inhibits bacterial dihydropteroate synthase, blocking folate synthesis. Trimethoprim inhibits bacterial dihydrofolate reductase, blocking reduction of dihydrofolate to tetrahydrofolate. Sequential blockade produces bactericidal synergy.
Each 5 mL suspension contains 250 mg erythromycin base and 600 mg sulfisoxazole; typical adult dose is 10 mL (2 tsp) every 6 hours, not to exceed 40 mL/day.
1 double-strength tablet (160 mg trimethoprim / 800 mg sulfamethoxazole) orally every 12 hours for 10-14 days.
None Documented
None Documented
Erythromycin: 1.5-2 hours; Sulfisoxazole: 4-7 hours; clinical context: dose adjustment in renal impairment (CrCl <50 mL/min) needed for sulfisoxazole
SMX: 9-12 hours (increased in renal impairment); TMP: 8-11 hours (increased in renal impairment); both prolonged in elderly.
Renal: 70-80% as unchanged drug and active metabolite (sulfisoxazole); Biliary: 10-15% as metabolites; 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
Macrolide and Sulfonamide Antibiotic
Sulfonamide Antibiotic