Tobramycin and Piperacillin/Tazobactam Interaction
Drug interaction information between Tobramycin and Piperacillin/Tazobactam.
Tobramycin and Piperacillin/Tazobactam have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Tobramycin and Piperacillin/Tazobactam. This page displays the available source-record category and label text. The category is not an individual risk estimate or medication-combination direction.
How They Interact
In patients on dialysis, piperacillin can chemically deactivate tobramycin in the blood, making the antibiotic less effective.
FDA Label Information
7 DRUG INTERACTIONS • ZOSYN administration can significantly reduce tobramycin concentrations in hemodialysis patients. Monitor tobramycin concentrations in these patients. In vivo inactivation : When aminoglycosides are administered in conjunction with piperacillin to patients with end-stage renal disease requiring hemodialysis, the concentrations of the aminoglycosides (especially tobramycin) may be significantly reduced and should be monitored.
Piperacillin/Tazobactam Also Interacts With
- Probenecid moderate
- Methotrexate minor
- Vancomycin minor
- Gentamicin minor
- Amikacin minor
Frequently Asked Questions
What SPL severity band is on file for Tobramycin + Piperacillin/Tazobactam?
Compiled FDA labeling labels this pair minor. That is a source-record field, not an individual medication-combination decision.
Which drug in this pair has the larger labeled-interaction portfolio?
Piperacillin/Tazobactam has 7 labeled pairs on file vs Tobramycin's 2. In the minor band specifically: Tobramycin has 1; Piperacillin/Tazobactam has 6 (also Methotrexate, Vancomycin, Gentamicin, Amikacin).
What mechanism field is on file for Tobramycin and Piperacillin/Tazobactam?
In patients on dialysis, piperacillin can chemically deactivate tobramycin in the blood, making the antibiotic less effective.
Tobramycin carries more major-labeled pairs than Piperacillin/Tazobactam
SPL source-record counts only. This page's band is minor · classes on file: Tobramycin (Aminoglycoside Antibiotic); Piperacillin/Tazobactam (Penicillin / Beta-Lactamase Inhibitor).
Tobramycin has 1 major-labeled pair vs Piperacillin/Tazobactam's 0. This page itself is in the minor band, not the major band.
1 major · 0 moderate · 1 minor · 2 total
Tobramycin has no other minor-band peer in this dataset besides Piperacillin/Tazobactam.
0 major · 1 moderate · 6 minor · 7 total
- Other minor peers for Piperacillin/Tazobactam
- Methotrexate
- Vancomycin
- Gentamicin
- Amikacin
Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. This registry does not provide individual medication-combination directions.
Read our methodology - how this data is sourced, computed, and verified.