Drug interactions
Glycerol phenylbutyrate + Quinidine
Severity: Minor
Glycerol phenylbutyrate and Quinidine: minor 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 a weak CYP3A4 inducer and may modestly lower quinidine concentrations. Quinidine's narrow therapeutic index means a reduced level could weaken arrhythmia control, though the effect is probably small.
What this interaction means in plain words
Glycerol phenylbutyrate and Quinidine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Glycerol phenylbutyrate belongs to Miscellaneous; Quinidine belongs to Anti Parasitic.
Why it happens
Weak induction of CYP3A4 increases quinidine metabolism.
What to do
Monitor the clinical response and ECG, with quinidine levels if available, after starting or stopping glycerol phenylbutyrate. Adjust the quinidine dose if efficacy falls.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Quinidine
- Adagrasib + Quinidine Contraindicated
- Arsenic trioxide + Quinidine Contraindicated
- Artemether / lumefantrine + Quinidine Contraindicated
- Chloroquine + Quinidine Contraindicated
- Dofetilide + Quinidine Contraindicated
- Dronedarone + Quinidine 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 Quinidine?
MediHelp rates the interaction as minor. Glycerol phenylbutyrate and Quinidine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Glycerol phenylbutyrate is a weak CYP3A4 inducer and may modestly lower quinidine concentrations. Quinidine's narrow therapeutic index means a reduced level could weaken arrhythmia control, though the effect is probably small.
How serious is the interaction between Glycerol phenylbutyrate and Quinidine?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor the clinical response and ECG, with quinidine levels if available, after starting or stopping glycerol phenylbutyrate. Adjust the quinidine dose if efficacy falls.
What other medicines interact with Quinidine?
MediHelp also lists interactions of Quinidine with, for example, Adagrasib, Arsenic trioxide, Artemether / lumefantrine. The full list is on the Quinidine page.
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