Adult Patients: The usual total daily dose of piperacillin/tazobactam for adults is 3.375 g every six hours totaling 13.5 g (12.0 g piperacillin/1.5 g tazobactam). The usual duration of piperacillin/tazobactam treatment is from 7 to 10 days.
Piperacillin/Tazobactam should be administered by intravenous infusion over 30 minutes.
Nosocomial Pneumonia: Initial presumptive treatment of patients with nosocomial pneumonia should start with piperacillin/tazobactam at a dosage of 4.5 g every six hours plus an aminoglycoside, totaling 18.0 g (16.0 g piperacillin/2.0 g tazobactam). The recommended duration of piperacillin/tazobactam treatment for nosocomial pneumonia is 7 to 14 days. Treatment with the aminoglycoside should be continued in patients from whom P. aeruginosa is isolated.
Renal Impairment: In patients with renal impairment (creatinine clearance ≤ 40 mL/min) and dialysis patients (hemodialysis and CAPD), the intravenous dose of piperacillin/tazobactam should be reduced to the degree of actual renal function impairment. The recommended daily doses of piperacillin/tazobactam for patients with renal impairment are as follows: See Table 3.

For patients on hemodialysis, the maximum dose is 2.25 g every twelve hours for all indications other than nosocomial pneumonia and 2.25 g every eight hours for nosocomial pneumonia. Since hemodialysis removes 30% to 40% of the administered dose, an additional dose of 0.75 g piperacillin/tazobactam (0.67 g piperacillin/0.08 g tazobactam) should be administered following each dialysis period on hemodialysis days. No additional dosage of piperacillin/tazobactam is necessary for CAPD patients.
Pediatric Patients: For children with appendicitis and/or peritonitis 9 months of age or older, weighing up to 40 kg, and with normal renal function, the recommended piperacillin/tazobactam dosage is 100 mg piperacillin/12.5 mg tazobactam per kilogram of body weight, every 8 hours. For pediatric patients between 2 months and 9 months of age, the recommended piperacillin/tazobactam dosage based on pharmacokinetic modeling, is 80 mg piperacillin/10 mg tazobactam per kilogram of body weight, every 8 hours. Pediatric patients weighing over 40 kg and with normal renal function should receive the adult dose.
It has not been determined how to adjust piperacillin/tazobactam dosage in pediatric patients with renal impairment.