Drug interactions
Glycerol phenylbutyrate + Haloperidol
Severity: Moderate
Glycerol phenylbutyrate and Haloperidol: 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
Glycerol phenylbutyrate is used to lower ammonia in urea cycle disorders, and haloperidol has been reported to raise ammonia levels. This may reduce disease control and risk hyperammonemic episodes.
What this interaction means in plain words
Glycerol phenylbutyrate and Haloperidol 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; Haloperidol belongs to Central Nervous System.
Why it happens
Haloperidol may increase blood ammonia, opposing the nitrogen-scavenging effect of glycerol phenylbutyrate; the mechanism is not fully established.
What to do
Monitor plasma ammonia closely when haloperidol is started or adjusted, and adjust the phenylbutyrate dose as indicated. Consider an alternative antipsychotic if ammonia control worsens.
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 Haloperidol
- Dofetilide + Haloperidol Contraindicated
- Dronedarone + Haloperidol Contraindicated
- Haloperidol + Ibutilide Contraindicated
- Haloperidol + Levoketoconazole Contraindicated
- Haloperidol + Panobinostat Contraindicated
- Haloperidol + Pimozide Contraindicated
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 Haloperidol?
MediHelp rates the interaction as moderate. Glycerol phenylbutyrate and Haloperidol 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 is used to lower ammonia in urea cycle disorders, and haloperidol has been reported to raise ammonia levels. This may reduce disease control and risk hyperammonemic episodes.
How serious is the interaction between Glycerol phenylbutyrate and Haloperidol?
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 plasma ammonia closely when haloperidol is started or adjusted, and adjust the phenylbutyrate dose as indicated. Consider an alternative antipsychotic if ammonia control worsens.
What other medicines interact with Haloperidol?
MediHelp also lists interactions of Haloperidol with, for example, Dofetilide, Dronedarone, Ibutilide. The full list is on the Haloperidol page.
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