Drug Interaction Report

Probenecid and Cefprozil: Interaction Details

A pharmacist-reviewed analysis of the Probenecid and Cefprozil interaction: the documented clinical effects, severity rating, onset, mechanism, and management considerations, with cited references throughout.

AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature

Probenecid

No brand names on record
+

Cefprozil

Cefzil®
Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by
Dr. Brian Staiger, PharmD, BCPS
Updated Aug 8, 2026
Editorial policy · Data sources
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Interaction severity
Moderate
Can be significant — usually manageable with monitoring.
How we grade severity & evidence

Severity levels

  • Contraindicated: These should generally not be used together.
  • Major: Potentially serious — often needs a change or close monitoring.
  • Moderate: Can be significant — usually manageable with monitoring.
  • Minor: Usually limited clinical impact.

Evidence grades

  • Established: Well documented — supported by controlled studies or strong clinical data.
  • Probable: Good supporting evidence, though not definitively proven.
  • Suspected: Some evidence suggests this interaction, but it is not well established.
  • Possible: Limited or conflicting evidence; the interaction may occur.
  • Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.

Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.

Of 59 documented Probenecid interactions, 22 are rated moderate — including this one.
Onset
delayed
Evidence
probable
Severity
Moderate

What happens

Increased serum cefprozil levels

Interaction Deep Dive

Probenecid has been shown to reduce the renal clearance of many cephalosporins2. Coadministration of cefprozil with probenecid has been shown to result in increased cefprozil Cmax, half-life, area under the concentration-time curve (AUC), and decreased clearance when given concurrently with probenecid 13.

Why it happens (mechanism)

Decreased cefprozil clearance

Literature reports

1 report — tap to read

a) The pharmacokinetic interactions between cefprozil and food, propantheline, metoclopramide, and probenecid were studied in 15 healthy volunteers. Each subject received cefprozil 1000 mg after fasting, pretreatment with metoclopramide or propantheline, after breakfast, or after probenecid 1 gram. Coadministration of probenecid with cefprozil resulted in significant increases in cefprozil maximum concentration (Cmax), median time to maximum concentration (Tmax), area under the concentration-time curve (AUC), half-life, and mean residence time after oral administration. In addition, a significant decrease in renal clearance of cefprozil of approximately 60% was observed during coadministration with probenecid 1.

Common questions

Can I take Probenecid and Cefprozil together?

Increased serum cefprozil levels Always confirm with your pharmacist or prescriber before making any change.

How serious is the Probenecid and Cefprozil interaction?

It is rated moderate. Can be significant — usually manageable with monitoring.

How quickly could this interaction happen?

The documented onset is "delayed". Effects tend to build up gradually over days to weeks.

How strong is the evidence for this interaction?

The evidence is graded "probable". Good supporting evidence, though not definitively proven.

From our Q&A

Real reader questions about these medications, each personally answered by our pharmacist:

Questions for your pharmacist

  • Does my dose of Probenecid or Cefprozil need adjusting while I take them together?
  • What symptoms should prompt me to call you or my prescriber right away?
  • Does the timing of my doses matter for this combination?
  • Is there anything you'd monitor while I'm on both?

References (3)

  1. Shukla UA, Pittman KA, & Barbhaiya RH: Pharmacokinetic interactions of cefprozil with food, propantheline, metoclopramide, and probenecid in healthy volunteers. J Clin Pharmacol 1992; 32:725-731. PubMed
  2. Mischler TW, Sugerman AA, Willard DA, et al: Influence of probenecid and food on the bioavailability of cephradine in normal male subjects. J Clin Pharmacol 1974; 14:604-611. DOI
  3. Product Information: Cefzil(R), cefprozil. Bristol Laboratories, Princeton, NJ, 1995. DailyMed
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Probenecid

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Cefprozil

Keep reading about Cefprozil

All Cefprozil interactions (27) Cefprozil drug information
Also serious with: Cholera Vaccine, Live Desogestrel Dienogest Drospirenone
Beyond drug–drug

These medications also interact with supplements

Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:

Probenecid + Activated Charcoal Asarabacca Siberian Cocklebur African Wild Potato Aristolochia Banderol Caffeic Acid Coffee Charcoal + 22 more
Cefprozil + Activated Charcoal Asarabacca Siberian Cocklebur African Wild Potato Aristolochia Bacillus Coagulans Bacillus Subtilis Banderol + 52 more

major · moderate · minor — check everything you take with our drug–supplement interaction checker.

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This information is for education, not a substitute for professional medical advice. Do not start, stop, or change any medication without talking to your pharmacist or prescriber.