Drug interactions
Diltiazem + Levoketoconazole
Severity: Major
Diltiazem and Levoketoconazole: 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
Both drugs are CYP3A4 substrates and inhibitors, so each can raise the other's exposure. Higher diltiazem levels can cause bradycardia, AV block, hypotension and additive negative inotropy, and higher levoketoconazole exposure raises the risk of QT prolongation and hepatotoxicity.
What this interaction means in plain words
Diltiazem and Levoketoconazole 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.
Diltiazem belongs to Cardiovascular; Levoketoconazole belongs to Endocrine.
Why it happens
Mutual inhibition of CYP3A4-mediated metabolism, with additive negative inotropic and conduction effects.
What to do
Avoid the combination if possible; if it is needed, monitor heart rate, blood pressure, ECG (QTc) and liver tests, and reduce the diltiazem dose as needed. Consider an alternative antihypertensive or rate-control agent.
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 Diltiazem
- Diltiazem + Flibanserin Contraindicated
- Diltiazem + Ivabradine Contraindicated
- Diltiazem + Lomitapide Contraindicated
- Diltiazem + Lonafarnib Contraindicated
- Acebutolol + Diltiazem Major
- Alfentanil + Diltiazem Major
Other interactions of Levoketoconazole
- Alfuzosin + Levoketoconazole Contraindicated
- Alprazolam + Levoketoconazole Contraindicated
- Amiodarone + Levoketoconazole Contraindicated
- Avanafil + Levoketoconazole Contraindicated
- Cisapride + Levoketoconazole Contraindicated
- Clarithromycin + Levoketoconazole Contraindicated
Frequently asked questions
Can I take Diltiazem with Levoketoconazole?
MediHelp rates the interaction as major. Diltiazem and Levoketoconazole 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 are CYP3A4 substrates and inhibitors, so each can raise the other's exposure. Higher diltiazem levels can cause bradycardia, AV block, hypotension and additive negative inotropy, and higher levoketoconazole exposure raises the risk of QT prolongation and hepatotoxicity.
How serious is the interaction between Diltiazem and Levoketoconazole?
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 the combination if possible; if it is needed, monitor heart rate, blood pressure, ECG (QTc) and liver tests, and reduce the diltiazem dose as needed. Consider an alternative antihypertensive or rate-control agent.
What other medicines interact with Diltiazem?
MediHelp also lists interactions of Diltiazem with, for example, Flibanserin, Ivabradine, Lomitapide. The full list is on the Diltiazem page.
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