Cefazolin and Piperacillin and tazobactam interaction
Cefazolin and Piperacillin and tazobactam: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Piperacillin and tazobactam (Piperacillin and Tazobactam and Sodium Chloride) label · effective 2026-05-08
Piperacillin and Tazobactam for Injection and Sodium Chloride Injection is contraindicated in patients with a history of allergic reactions to any of the penicillins, cephalosporins, or betalactamase inhibitors.
Patients with a history of allergic reactions to any of the penicillins, cephalosporins, or beta-lactamase inhibitors.
Nephrotoxicity in critically ill patients has been observed; the use of piperacillin and tazobactam was found to be an independent risk factor for renal failure and was associated with delayed recovery of renal function as compared to other beta-lactam antibacterial drugs in a randomized, multicenter, controlled trial in critically ill patients.
Hematologic Adverse Reactions Bleeding manifestations have occurred in some patients receiving beta-lactam drugs, including piperacillin.
Nephrotoxicity in Critically Ill Patients The use of piperacillin and tazobactam was found to be an independent risk factor for renal failure and was associated with delayed recovery of renal function as compared to other beta-lactam antibacterial drugs in a randomized, multicenter, controlled trial in critically ill patients [see Adverse Reactions (6.1) ].
From the Cefazolin label · effective 2026-02-27
Hypersensitivity to cefazolin or other cephalosporin class antibacterial drugs, penicillins, or other beta-lactams (4.1)
Hypersensitivity to Cefazolin or the Cephalosporin Class of Antibacterial Drugs, Penicillins, or Other Beta-lactams Cefazolin for Injection is contraindicated in patients who have a history of immediate hypersensitivity reactions (e.g., anaphylaxis, serious skin reactions) to cefazolin or the cephalosporin class of antibacterial drugs, penicillins, or other beta-lactams…
Hypersensitivity Reactions to Cefazolin, Cephalosporins, Penicillins, or Other Beta-lactams Serious and occasionally fatal hypersensitivity (anaphylactic) reactions have been reported in patients receiving beta-lactam antibacterial drugs.
• Hypersensitivity Reactions: Cross-hypersensitivity may occur in up to 10% of patients with a history of penicillin allergy.
Exercise caution if this product is to be given to penicillin-sensitive patients because cross-hypersensitivity among beta-lactam antibacterial drugs has been clearly documented and may occur in up to 10% of patients with a history of penicillin allergy.
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Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.