Drug interactions
Diazepam + Voriconazole
Severity: Major
Diazepam and Voriconazole: major interaction.
Last updated Sources: US FDA label
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
Voriconazole inhibits CYP3A4 and CYP2C19, both involved in diazepam metabolism, and can substantially increase and prolong diazepam exposure. This may result in excessive sedation and respiratory depression.
What this interaction means in plain words
Diazepam and Voriconazole 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.
Diazepam belongs to Musculoskeletal; Voriconazole belongs to Anti Fungals.
Why it happens
Voriconazole inhibits CYP2C19 and CYP3A4, decreasing diazepam clearance.
What to do
Reduce the diazepam dose and monitor sedation and respiratory status closely during co-treatment. Consider lorazepam, which is not dependent on CYP metabolism, if a benzodiazepine is required.
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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References
Other interactions of Diazepam
Other interactions of Voriconazole
- Avanafil + Voriconazole Contraindicated
- Butabarbital + Voriconazole Contraindicated
- Carbamazepine + Voriconazole Contraindicated
- Conivaptan + Voriconazole Contraindicated
- Dihydroergotamine intranasal + Voriconazole Contraindicated
- Dihydroergotamine + Voriconazole Contraindicated
Frequently asked questions
Can I take Diazepam with Voriconazole?
MediHelp rates the interaction as major. Diazepam and Voriconazole 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. Voriconazole inhibits CYP3A4 and CYP2C19, both involved in diazepam metabolism, and can substantially increase and prolong diazepam exposure. This may result in excessive sedation and respiratory depression.
How serious is the interaction between Diazepam and Voriconazole?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Reduce the diazepam dose and monitor sedation and respiratory status closely during co-treatment. Consider lorazepam, which is not dependent on CYP metabolism, if a benzodiazepine is required.
What other medicines interact with Diazepam?
MediHelp also lists interactions of Diazepam with, for example, Calcium / magnesium / potassium / sodium oxybates, Alfentanil, Alprazolam. The full list is on the Diazepam page.
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