Drug interactions
Clarithromycin + Dofetilide
Severity: Contraindicated
Clarithromycin and Dofetilide: contraindicated 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 can prolong the QT interval, and clarithromycin may also impair dofetilide elimination, raising its concentration. This substantially increases the risk of torsades de pointes.
What this interaction means in plain words
Clarithromycin and Dofetilide are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two.
Clarithromycin belongs to Anti Bacterial; Dofetilide belongs to Cardiovascular.
Why it happens
Additive QT prolongation, with possible increased dofetilide exposure through inhibition of renal cation transport and CYP3A4.
What to do
Avoid the combination; use an antibiotic without QT effects and monitor ECG and electrolytes if dofetilide is continued.
What to ask your pharmacist
- Is there an alternative to one of these two medicines for me?
- If both are essential, who is monitoring me and how often?
- Which symptoms mean I should stop and seek help straight away?
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References
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 Dofetilide
- Amiodarone + Dofetilide Contraindicated
- Amisulpride + Dofetilide Contraindicated
- Amlodipine-hydrochlorothiazide-valsartan + Dofetilide Contraindicated
- Amlodipine-olmesartan-hydrochlorothiazide + Dofetilide Contraindicated
- Candesartan-hydrochlorothiazide + Dofetilide Contraindicated
- Captopril-hydrochlorothiazide + Dofetilide Contraindicated
Frequently asked questions
Can I take Clarithromycin with Dofetilide?
MediHelp rates the interaction as contraindicated. Clarithromycin and Dofetilide are not normally used together. Taking them at the same time is expected to cause harm or make one of them unsafe, so a different medicine is usually chosen for one of the two. Both drugs can prolong the QT interval, and clarithromycin may also impair dofetilide elimination, raising its concentration. This substantially increases the risk of torsades de pointes.
How serious is the interaction between Clarithromycin and Dofetilide?
MediHelp rates it contraindicated, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination; use an antibiotic without QT effects and monitor ECG and electrolytes if dofetilide is continued.
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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