Piperacillin and Tazobactam for injection is administered by intravenous infusion over 30 minutes. The usual total daily dose of Piperacillin and Tazobactam for injection for adults is 3.375 g every six hours totaling 13.5 g (12 g piperacillin/1.5 g tazobactam). Or as prescribed by the physician.