Amoxicillin and Piperacillin and tazobactam interaction

Amoxicillin 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.

Major

Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.

What the FDA labels say

From the Amoxicillin label · effective 2026-07-07

Major

AMOXIL is contraindicated in patients who have experienced a serious hypersensitivity reaction (e.g., anaphylaxis or Stevens-Johnson syndrome) to AMOXIL or to other β-lactam antibacterial drugs (e.g., penicillins and cephalosporins).

Contraindicationsby drug classView label on DailyMed
Major

History of a serious hypersensitivity reaction (e.g., anaphylaxis or Stevens-Johnson syndrome) to Amoxicillin or to other beta-lactams (e.g., penicillins or cephalosporins).

Contraindicationsby drug classView label on DailyMed

From the Piperacillin and tazobactam (Piperacillin and Tazobactam and Sodium Chloride) label · effective 2026-05-08

Moderate

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.

Warnings and precautionsby drug classView label on DailyMed
Moderate

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) ].

Warnings and precautionsby drug classView label on DailyMed
Moderate

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 ® ).

Drug interactionsby drug classView label on DailyMed
Minor

As with other penicillins, piperacillin and tazobactam may cause neuromuscular excitability or seizures.

Warnings and precautionsby drug classView label on DailyMed
Minor

Central Nervous System Adverse Reactions As with other penicillins, piperacillin and tazobactam may cause neuromuscular excitability or seizures.

Warnings and precautionsby drug classView label on DailyMed

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Not 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.