Comparative Pharmacology
Head-to-head clinical analysis: COTRIM D S versus ZOSYN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: COTRIM D S versus ZOSYN.
COTRIM D.S. vs ZOSYN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
COTRIM D.S. is a combination of sulfamethoxazole, a competitive inhibitor of dihydropteroate synthase, and trimethoprim, a reversible inhibitor of dihydrofolate reductase. This sequential blockade of folate synthesis leads to bactericidal activity.
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.
160 mg trimethoprim / 800 mg sulfamethoxazole (one double-strength tablet) 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: 9-12 hours (normal renal function). Trimethoprim: 8-11 hours. Both are prolonged in renal impairment (e.g., creatinine clearance <30 mL/min: >24 hours). Clinical context: dosing interval is typically 12 hours; dose adjustment required if CrCl <30 mL/min.
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)
Sulfamethoxazole: ~20% unchanged in urine, remainder as acetylated and glucuronide metabolites. Trimethoprim: ~50-80% unchanged in urine, remainder as oxidative metabolites. Both undergo renal excretion via glomerular filtration and tubular secretion. Total renal elimination: 70-90% of dose combined. Biliary/fecal: <10%.
Primarily renal; piperacillin 68% unchanged, tazobactam 80% unchanged; biliary/fecal excretion <10%
Category C
Category C
Antibiotic
Antibiotic