Drug interactions
Ketoconazole + Risperidone
Severity: Moderate
Ketoconazole and Risperidone: 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
Ketoconazole may modestly raise exposure to risperidone and its active metabolite, and both drugs can prolong the QT interval. This may increase the risk of extrapyramidal effects, sedation and arrhythmia.
What this interaction means in plain words
Ketoconazole and Risperidone 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.
Ketoconazole belongs to Anti Fungals; Risperidone belongs to Central Nervous System.
Why it happens
Ketoconazole inhibits P-glycoprotein and CYP3A4 handling of risperidone, with additive QT prolongation.
What to do
Monitor for extrapyramidal symptoms and sedation, and consider an ECG in patients with QT risk factors. Reduce the risperidone dose if adverse effects arise.
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 Ketoconazole
- Alfuzosin + Ketoconazole Contraindicated
- Alprazolam + Ketoconazole Contraindicated
- Avanafil + Ketoconazole Contraindicated
- Conivaptan + Ketoconazole Contraindicated
- Dihydroergotamine intranasal + Ketoconazole Contraindicated
- Dihydroergotamine + Ketoconazole Contraindicated
Other interactions of Risperidone
- Ibutilide + Risperidone Contraindicated
- Risperidone + Vandetanib Contraindicated
- Adagrasib + Risperidone Major
- Amiodarone + Risperidone Major
- Amisulpride + Risperidone Major
- Amoxapine + Risperidone Major
Frequently asked questions
Can I take Ketoconazole with Risperidone?
MediHelp rates the interaction as moderate. Ketoconazole and Risperidone 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. Ketoconazole may modestly raise exposure to risperidone and its active metabolite, and both drugs can prolong the QT interval. This may increase the risk of extrapyramidal effects, sedation and arrhythmia.
How serious is the interaction between Ketoconazole and Risperidone?
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 for extrapyramidal symptoms and sedation, and consider an ECG in patients with QT risk factors. Reduce the risperidone dose if adverse effects arise.
What other medicines interact with Ketoconazole?
MediHelp also lists interactions of Ketoconazole with, for example, Alfuzosin, Alprazolam, Avanafil. The full list is on the Ketoconazole page.
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