Ampicillin and Piperacillin and tazobactam interaction
Ampicillin 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 Ampicillin label · effective 2026-07-27
CONTRAINDICATIONS The use of Ampicillin is contraindicated in individuals with a history of serious hypersensitivity reactions (e.g., anaphylaxis or Stevens-Johnson syndrome) to ampicillin or to other beta-lactam antibacterial drugs.
From the Piperacillin and tazobactam (Piperacillin and Tazobactam and Sodium Chloride) label · effective 2026-05-08
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.
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) ].
As with other penicillins, the administration of piperacillin and tazobactam may result in a false-positive reaction for glucose in the urine using a copper-reduction method (CLINITEST ® ).
As with other penicillins, piperacillin and tazobactam may cause neuromuscular excitability or seizures.
Central Nervous System Adverse Reactions As with other penicillins, piperacillin and tazobactam may cause neuromuscular excitability or seizures.
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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.