piperacillin and tazobactam (Zosyn) (cont.)

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  • Piperacillin and tazobactam for injection is supplied as a powder for reconstitution (mixing).
  • Powder for solution for injection: 2.25, 3.375, 4.5, 40.5 g

STORAGE: Piperacillin and tazobactam vials should be stored at controlled room temperature, between 20 C to 25 C (68 F to 77 F), before reconstitution.

ADULT DOSING: Piperacillin and tazobactam should be administered by intravenous infusion (IV) over 30 minutes. The usual daily dose for adults is 3.375 g every six hours (total daily dose 13.5 g).

  • Nosocomial pneumonia: The usual starting dose is 4.5 g intravenously every 6 hours plus an aminoglycoside for 7-14 days.
  • Community-acquired pneumonia: The usual recommended dose is 3.375 g intravenously every 6 hours for 7-10 days.
  • Skin and soft tissue infection: The usual recommended dose is 3.375 mg intravenously every 6-8 hours for 7-14 days.
  • Diverticulitis, intra-abdominal abscess, peritonitis: The usual recommended dose is 3.375 g intravenously every 6 hours for 7-10 days.

Piperacillin and tazobactam requires dose adjustment in patients with reduced kidney function.

PEDIATRIC DOSING: Manufacturer's recommendation for the treatment of appendicitis and/or peritonitis includes:

  • < 2 months: safety and efficacy is not established
  • Infants 2-9 months: 80 mg/kg IV every 8 hours
  • Infants and children =9 months, weighing =40 kg with normal renal function: 100 mg/kg IV every 8 hours
  • Pediatric patients > 40 kg with normal renal function: same as adult dose


  • Probenecid may inhibit the renal tubular secretion (elimination via the kidneys) of piperacillin/tazobactam. This may cause higher, prolonged blood levels of piperacillin/tazobactam. The half-life of piperacillin is prolonged by 21% and the half-life of tazobactam by 71%.
  • Piperacillin/tazobactam may inhibit platelet aggregation (formation of a blood clot) which may increase the risk for bleeding. Co-administration with blood thinning agents such as warfarin (Coumadin) requires close monitoring for signs or symptoms of bleeding.
  • Piperacillin/tazobactam may prolong the neuromuscular blockade of vecuronium (Norcuron).
  • Piperacillin/tazobactam may decrease the renal (kidney) elimination of methotrexate (Trexall). Patients on concurrent therapy with methotrexate should be monitored frequently for signs or symptoms of methotrexate toxicity.
Medically Reviewed by a Doctor on 12/12/2014

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