Comparative Pharmacology
Head-to-head clinical analysis: SULFAMETHOXAZOLE AND TRIMETHOPRIM DOUBLE STRENGTH versus ZOSYN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: SULFAMETHOXAZOLE AND TRIMETHOPRIM DOUBLE STRENGTH versus ZOSYN.
SULFAMETHOXAZOLE AND TRIMETHOPRIM DOUBLE STRENGTH vs ZOSYN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Sulfamethoxazole inhibits bacterial dihydropteroate synthase, blocking folic acid synthesis. Trimethoprim inhibits bacterial dihydrofolate reductase, blocking reduction of dihydrofolate to tetrahydrofolate. Sequential blockade produces bactericidal effect.
Piperacillin, a semisynthetic penicillin, inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs). Tazobactam, a beta-lactamase inhibitor, inactivates beta-lactamases, preventing piperacillin degradation.
One double-strength tablet (160 mg trimethoprim/800 mg sulfamethoxazole) orally every 12 hours.
3.375 g (piperacillin 3 g / tazobactam 0.375 g) intravenously every 6 hours over 30 minutes; for nosocomial pneumonia, 4.5 g intravenously every 6 hours.
None Documented
None Documented
Sulfamethoxazole: 9-11 hours; trimethoprim: 8-11 hours. In severe renal impairment (CrCl <15 mL/min), half-life prolongs significantly (up to 30 hours for trimethoprim).
Piperacillin ~0.7-1.2 h; tazobactam ~0.7-1.0 h; extended in renal impairment (piperacillin up to 3.3 h, tazobactam up to 4.7 h in CrCl <20 mL/min)
Both sulfamethoxazole and trimethoprim are primarily excreted via the kidneys. Sulfamethoxazole: ~30% as unchanged drug, ~50% as N4-acetyl metabolite; trimethoprim: ~80% as unchanged drug. Fecal elimination is minimal (<5%).
Primarily renal; piperacillin 68% unchanged, tazobactam 80% unchanged; biliary/fecal excretion <10%
Category D/X
Category C
Antibiotic
Antibiotic