Comparative Pharmacology
Head-to-head clinical analysis: XIFAXAN versus ZOSYN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: XIFAXAN versus ZOSYN.
XIFAXAN vs ZOSYN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Rifaximin is a non-systemic, gut-selective antibiotic that inhibits bacterial RNA synthesis by binding to the beta-subunit of bacterial DNA-dependent RNA polymerase, thereby reducing bacterial overgrowth and altering gut microbiota composition.
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.
550 mg orally twice daily for traveler's diarrhea; 550 mg orally three times daily for hepatic encephalopathy.
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 for rifaximin after oral administration ranges from 1.8 to 10 hours, with a mean of approximately 6 hours. The half-life is extended in hepatic impairment due to reduced clearance, and no dosage adjustment is recommended for renal impairment.
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)
Rifaximin is primarily eliminated unchanged in feces via biliary excretion (approximately 97% of an oral dose). Renal excretion of unchanged drug accounts for <0.4% of the dose. Fecal elimination is the major route.
Primarily renal; piperacillin 68% unchanged, tazobactam 80% unchanged; biliary/fecal excretion <10%
Category C
Category C
Antibiotic
Antibiotic