Drug interactions
Clarithromycin + Vandetanib
Severity: Major
Clarithromycin and Vandetanib: 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
Vandetanib markedly prolongs the QT interval, and clarithromycin adds further prolongation, raising the risk of torsades de pointes and sudden death. Clarithromycin may also increase vandetanib exposure.
What this interaction means in plain words
Clarithromycin and Vandetanib 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.
Clarithromycin belongs to Anti Bacterial; Vandetanib belongs to Oncology.
Why it happens
Additive QT prolongation with CYP3A4 inhibition by clarithromycin.
What to do
Avoid the combination and use a non-QT-prolonging antibiotic. If unavoidable, perform frequent ECG monitoring and keep potassium and magnesium normal.
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 Clarithromycin
- Astemizole + Clarithromycin Contraindicated
- Avanafil + Clarithromycin Contraindicated
- Cisapride + Clarithromycin Contraindicated
- Clarithromycin + Colchicine Contraindicated
- Clarithromycin + Conivaptan Contraindicated
- Clarithromycin + Dihydroergotamine Contraindicated
Other interactions of Vandetanib
- Amiodarone + Vandetanib Contraindicated
- Amisulpride + Vandetanib Contraindicated
- Amitriptyline + Vandetanib Contraindicated
- Anagrelide + Vandetanib Contraindicated
- Asenapine + Vandetanib Contraindicated
- Chloroquine + Vandetanib Contraindicated
Frequently asked questions
Can I take Clarithromycin with Vandetanib?
MediHelp rates the interaction as major. Clarithromycin and Vandetanib 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. Vandetanib markedly prolongs the QT interval, and clarithromycin adds further prolongation, raising the risk of torsades de pointes and sudden death. Clarithromycin may also increase vandetanib exposure.
How serious is the interaction between Clarithromycin and Vandetanib?
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 and use a non-QT-prolonging antibiotic. If unavoidable, perform frequent ECG monitoring and keep potassium and magnesium normal.
What other medicines interact with Clarithromycin?
MediHelp also lists interactions of Clarithromycin with, for example, Astemizole, Avanafil, Cisapride. The full list is on the Clarithromycin page.
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