Drug interactions
Glycerol phenylbutyrate + Probenecid
Severity: Moderate
Glycerol phenylbutyrate and Probenecid: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Probenecid may inhibit the renal excretion of the phenylbutyrate metabolites phenylacetic acid and phenylacetylglutamine. Higher levels of phenylacetate may increase toxicity such as neurological effects, and urinary PAGN may no longer reflect dosing.
What this interaction means in plain words
Glycerol phenylbutyrate and Probenecid can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Glycerol phenylbutyrate belongs to Miscellaneous; Probenecid belongs to Genitourinary.
Why it happens
Probenecid inhibits renal tubular secretion of phenylbutyrate metabolites via organic anion transporters.
What to do
Monitor ammonia and plasma phenylacetate levels and for signs of phenylacetate toxicity such as somnolence, headache and nausea. Adjust the glycerol phenylbutyrate dose accordingly.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Probenecid
- Ketorolac intranasal + Probenecid Contraindicated
- Ketorolac + Probenecid Contraindicated
- Baricitinib + Probenecid Major
- Ceftazidime / avibactam + Probenecid Major
- Methotrexate + Probenecid Major
- Pralatrexate + Probenecid Major
Other interactions of Glycerol phenylbutyrate
- Dexamethasone + Glycerol phenylbutyrate Major
- Glycerol phenylbutyrate + Sodium valproate Major
- Glycerol phenylbutyrate + Valproic acid Major
- Cyclosporin + Glycerol phenylbutyrate Moderate
- Dexamethasone-neomycin-polymyxin + Glycerol phenylbutyrate Moderate
- Dexamethasone-tobramycin + Glycerol phenylbutyrate Moderate
Frequently asked questions
Can I take Glycerol phenylbutyrate with Probenecid?
MediHelp rates the interaction as moderate. Glycerol phenylbutyrate and Probenecid can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Probenecid may inhibit the renal excretion of the phenylbutyrate metabolites phenylacetic acid and phenylacetylglutamine. Higher levels of phenylacetate may increase toxicity such as neurological effects, and urinary PAGN may no longer reflect dosing.
How serious is the interaction between Glycerol phenylbutyrate and Probenecid?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor ammonia and plasma phenylacetate levels and for signs of phenylacetate toxicity such as somnolence, headache and nausea. Adjust the glycerol phenylbutyrate dose accordingly.
What other medicines interact with Probenecid?
MediHelp also lists interactions of Probenecid with, for example, Ketorolac intranasal, Ketorolac, Baricitinib. The full list is on the Probenecid page.
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