Drug interactions
Ketoconazole + Nortriptyline
Severity: Major
Ketoconazole and Nortriptyline: major 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
Both drugs can prolong the QT interval, and ketoconazole may raise nortriptyline levels. This increases arrhythmia risk and tricyclic adverse effects.
What this interaction means in plain words
Ketoconazole and Nortriptyline 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.
Ketoconazole belongs to Anti Fungals; Nortriptyline belongs to Central Nervous System.
Why it happens
Additive QT prolongation with possible CYP inhibition by ketoconazole reducing nortriptyline clearance.
What to do
Avoid if possible. If co-administered, check ECG and electrolytes and monitor nortriptyline levels or toxicity, reducing the dose as needed.
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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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 Nortriptyline
- Disopyramide + Nortriptyline Contraindicated
- Dofetilide + Nortriptyline Contraindicated
- Dronedarone + Nortriptyline Contraindicated
- Ibutilide + Nortriptyline Contraindicated
- Isocarboxazid + Nortriptyline Contraindicated
- Methylene blue + Nortriptyline Contraindicated
Frequently asked questions
Can I take Ketoconazole with Nortriptyline?
MediHelp rates the interaction as major. Ketoconazole and Nortriptyline 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. Both drugs can prolong the QT interval, and ketoconazole may raise nortriptyline levels. This increases arrhythmia risk and tricyclic adverse effects.
How serious is the interaction between Ketoconazole and Nortriptyline?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid if possible. If co-administered, check ECG and electrolytes and monitor nortriptyline levels or toxicity, reducing the dose as needed.
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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