What the FDA labels say about taking them together
Piperacillin/tazobactam and probenecid
Piperacillin/tazobactam's FDA label of July 21, 2025 names probenecid in its drug interactions section; the probenecid label PlainMeds reads does not name piperacillin/tazobactam. The piperacillin/tazobactam label: “Probenecid prolongs the half-lives of piperacillin and tazobactam and should not be co-administered with ZOSYN unless the benefit outweighs the risk.”
Check it at the source: the piperacillin/tazobactam FDA label on DailyMed (effective July 21, 2025, ONESOURCE SPECIALTY PHARMA LIMITED); the probenecid FDA label on DailyMed (effective January 5, 2021, Lannett Company, Inc.).
What does the piperacillin/tazobactam label say about probenecid?
Piperacillin/tazobactam label, drug interactionsMonitor tobramycin concentrations in these patients. ( 7.1 ) Probenecid prolongs the half-lives of piperacillin and tazobactam and should not be co-administered with piperacillin and tazobactam unless the benefit outweighs the risk. ( 7.2 ) Co-administration of piperacillin and tazobactam with vancomycin may increase the incidence of acute kidney injury.
Zosyn label (Baxter Healthcare Corporation, May 15, 2026), drug interactionsProbenecid prolongs the half-lives of piperacillin and tazobactam and should not be co-administered with ZOSYN unless the benefit outweighs the risk.
Source: FDA drug label (Zosyn, NDA050750), Baxter Healthcare Corporation, effective May 15, 2026 (SPL set 8db6bd91-2106-4bfd-8cc8-38aaf1e18d17), via openFDA
Source: FDA drug label (Piperacillin And Tazobactam And Sodium Chloride, NDA206056), B. Braun Medical Inc., effective May 8, 2026 (SPL set a63ca653-27d4-45fe-a744-77e0efe45220), via openFDA
Source: FDA drug label (piperacillin and tazobactam), ONESOURCE SPECIALTY PHARMA LIMITED, effective July 21, 2025 (SPL set 28258745-12e4-4f0f-b318-4a1a1bebc928), via openFDA; the full label on DailyMed
What does the probenecid label say about piperacillin/tazobactam?
Probenecid's label (effective January 5, 2021) does not name piperacillin/tazobactam in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Probenecid), Lannett Company, Inc., effective January 5, 2021 (SPL set ab497fd8-00c3-4364-b003-b39d21fbdf38), via openFDA; the full label on DailyMed
These are the labels' own sentences. PlainMeds does not grade interactions; a pharmacist or prescriber can say what they mean for one person's medicines.
Both medicines on the record
| Piperacillin/tazobactam | Probenecid | |
|---|---|---|
| Labeled for | Bacterial infections | Gout |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $3.49 per vial 3.375 g vial | $0.636 per tablet 500 mg tablet |
| Shortage now | A presentation being discontinued | No current entry |
Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)
What next?
- Check more medicines together
- up to five at once