Drug interactions
Glycerol phenylbutyrate + Sodium valproate
Severity: Major
Glycerol phenylbutyrate and Sodium valproate: major 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
Valproate can cause hyperammonemia and may antagonize the ammonia-lowering effect of glycerol phenylbutyrate in patients with urea cycle disorders. This may precipitate hyperammonemic crises.
What this interaction means in plain words
Glycerol phenylbutyrate and Sodium valproate can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Glycerol phenylbutyrate belongs to Miscellaneous; Sodium valproate belongs to Central Nervous System.
Why it happens
Valproate inhibits urea cycle enzyme function (e.g., via carnitine and N-acetylglutamate depletion), raising ammonia.
What to do
Avoid valproate in urea cycle disorders where possible. If used, monitor plasma ammonia closely and adjust the glycerol phenylbutyrate dose.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Glycerol phenylbutyrate
- Dexamethasone + Glycerol phenylbutyrate Major
- Glycerol phenylbutyrate + Valproic acid Major
- Cyclosporin + Glycerol phenylbutyrate Moderate
- Dexamethasone-neomycin-polymyxin + Glycerol phenylbutyrate Moderate
- Dexamethasone-tobramycin + Glycerol phenylbutyrate Moderate
- Fludrocortisone + Glycerol phenylbutyrate Moderate
Other interactions of Sodium valproate
Frequently asked questions
Can I take Glycerol phenylbutyrate with Sodium valproate?
MediHelp rates the interaction as major. Glycerol phenylbutyrate and Sodium valproate can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Valproate can cause hyperammonemia and may antagonize the ammonia-lowering effect of glycerol phenylbutyrate in patients with urea cycle disorders. This may precipitate hyperammonemic crises.
How serious is the interaction between Glycerol phenylbutyrate and Sodium valproate?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid valproate in urea cycle disorders where possible. If used, monitor plasma ammonia closely and adjust the glycerol phenylbutyrate dose.
What other medicines interact with Glycerol phenylbutyrate?
MediHelp also lists interactions of Glycerol phenylbutyrate with, for example, Dexamethasone, Valproic acid, Cyclosporin. The full list is on the Glycerol phenylbutyrate page.
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