Probenecid and Cephalexin Interaction
Drug interaction information between Probenecid and Cephalexin.
Probenecid and Cephalexin have a documented moderate interaction in FDA labeling.
FDA drug labeling documents a moderate-severity interaction between Probenecid and Cephalexin. 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
Probenecid blocks your kidneys from removing cephalexin from your body. This causes the antibiotic to build up to higher levels than intended.
FDA Label Information
( 7.1 ) Probenecid-The renal excretion of cephalexin is inhibited by probenecid. Co-administration of probenecid with cephalexin is not recommended. 7.2 Probenecid The renal excretion of cephalexin is inhibited by probenecid.
Probenecid Also Interacts With
- Ketorolac major
- Levofloxacin major
- Amoxicillin moderate
- Amoxicillin/Clavulanate moderate
- Ceftazidime/Avibactam moderate
Frequently Asked Questions
What SPL severity band is on file for Probenecid + Cephalexin?
Compiled FDA labeling labels this pair moderate. That is a source-record field, not an individual medication-combination decision.
Which drug in this pair has the larger labeled-interaction portfolio?
Probenecid has 37 labeled pairs on file vs Cephalexin's 2. In the moderate band specifically: Probenecid has 12 (also Amoxicillin, Amoxicillin/Clavulanate, Ceftazidime/Avibactam, Cefuroxime); Cephalexin has 1.
What mechanism field is on file for Probenecid and Cephalexin?
Probenecid blocks your kidneys from removing cephalexin from your body. This causes the antibiotic to build up to higher levels than intended.
Probenecid carries more major-labeled pairs than Cephalexin
SPL source-record counts only. This page's band is moderate · classes on file: Probenecid (Uricosuric Agent); Cephalexin (First-Generation Cephalosporin).
Probenecid has 2 major-labeled pairs vs Cephalexin's 0. This page itself is in the moderate band, not the major band.
2 major · 12 moderate · 23 minor · 37 total
- Other moderate peers for Probenecid
- Amoxicillin
- Amoxicillin/Clavulanate
- Ceftazidime/Avibactam
- Cefuroxime
0 major · 1 moderate · 1 minor · 2 total
Cephalexin has no other moderate-band peer in this dataset besides Probenecid.
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.