Drug interactions
Valproic acid + Voriconazole
Severity: Minor
Valproic acid and Voriconazole: 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
Valproic acid may modestly raise voriconazole exposure, but the clinical relevance is uncertain and no meaningful toxicity has been established. Voriconazole is mainly cleared by CYP2C19, with smaller contributions from CYP2C9 and CYP3A4.
What this interaction means in plain words
Valproic acid and Voriconazole have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Valproic acid belongs to Central Nervous System; Voriconazole belongs to Anti Fungals.
Why it happens
Possible weak inhibition of CYP2C9 by valproic acid reducing voriconazole clearance; the effect is not well established.
What to do
No routine dose change is needed. Check voriconazole trough levels and watch for visual, hepatic or neurological adverse effects if the patient shows signs of voriconazole toxicity.
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 Voriconazole
- Avanafil + Voriconazole Contraindicated
- Butabarbital + Voriconazole Contraindicated
- Carbamazepine + Voriconazole Contraindicated
- Conivaptan + Voriconazole Contraindicated
- Dihydroergotamine intranasal + Voriconazole Contraindicated
- Dihydroergotamine + Voriconazole Contraindicated
Other interactions of Valproic acid
- Ertapenem + Valproic acid Contraindicated
- Imipenem / cilastatin / relebactam + Valproic acid Contraindicated
- Imipenem / cilastatin + Valproic acid Contraindicated
- Meropenem / vaborbactam + Valproic acid Contraindicated
- Meropenem + Valproic acid Contraindicated
- Calcium / magnesium / potassium / sodium oxybates + Valproic acid Major
Frequently asked questions
Can I take Valproic acid with Voriconazole?
MediHelp rates the interaction as minor. Valproic acid and Voriconazole have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Valproic acid may modestly raise voriconazole exposure, but the clinical relevance is uncertain and no meaningful toxicity has been established. Voriconazole is mainly cleared by CYP2C19, with smaller contributions from CYP2C9 and CYP3A4.
How serious is the interaction between Valproic acid and Voriconazole?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No routine dose change is needed. Check voriconazole trough levels and watch for visual, hepatic or neurological adverse effects if the patient shows signs of voriconazole toxicity.
What other medicines interact with Voriconazole?
MediHelp also lists interactions of Voriconazole with, for example, Avanafil, Butabarbital, Carbamazepine. The full list is on the Voriconazole page.
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