Comparative Pharmacology
Head-to-head clinical analysis: SYNERCID versus ZOSYN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: SYNERCID versus ZOSYN.
SYNERCID vs ZOSYN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Synercid is a combination of two streptogramin antibiotics, quinupristin and dalfopristin, which bind to the 50S bacterial ribosome and inhibit protein synthesis. Quinupristin binds to the 23S rRNA near the peptidyl transferase center, while dalfopristin binds to a nearby site and enhances quinupristin's binding. The synergistic effect results in irreversible inhibition of bacterial protein synthesis.
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.
7.5 mg/kg IV every 8 hours, administered as a 60-minute infusion.
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
The terminal elimination half-life is approximately 0.85 hours for dalfopristin and 1.3 hours for quinupristin; however, the active metabolite of quinupristin has a half-life of about 3.5 hours, supporting twice-daily dosing.
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)
Primarily hepatic metabolism with biliary excretion; approximately 15% of the dalfopristin dose and 32% of the quinupristin dose are excreted unchanged in feces; renal excretion is minor (<5% for both components).
Primarily renal; piperacillin 68% unchanged, tazobactam 80% unchanged; biliary/fecal excretion <10%
Category C
Category C
Antibiotic
Antibiotic