Drug interactions
Clarithromycin + Tolvaptan
Severity: Major
Clarithromycin and Tolvaptan: major interaction.
Last updated Sources: UK SmPC
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
Clarithromycin markedly increases tolvaptan exposure, which may cause excessive aquaresis, dehydration, hypernatremia and overly rapid sodium correction.
What this interaction means in plain words
Clarithromycin and Tolvaptan 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; Tolvaptan belongs to Endocrine.
Why it happens
Strong CYP3A4 inhibition reduces tolvaptan clearance.
What to do
Avoid the combination per labeling for strong CYP3A4 inhibitors, or use an alternative antibiotic. If unavoidable, monitor serum sodium and fluid status closely and reduce the tolvaptan dose as labeling advises.
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 Clarithromycin
- Astemizole + Clarithromycin Contraindicated
- Avanafil + Clarithromycin Contraindicated
- Cisapride + Clarithromycin Contraindicated
- Clarithromycin + Colchicine Contraindicated
- Clarithromycin + Conivaptan Contraindicated
- Clarithromycin + Dihydroergotamine Contraindicated
Other interactions of Tolvaptan
- Atazanavir + Tolvaptan Contraindicated
- Ceritinib + Tolvaptan Contraindicated
- Cobicistat + Tolvaptan Contraindicated
- Conivaptan + Tolvaptan Contraindicated
- Darunavir + Tolvaptan Contraindicated
- Idelalisib + Tolvaptan Contraindicated
Frequently asked questions
Can I take Clarithromycin with Tolvaptan?
MediHelp rates the interaction as major. Clarithromycin and Tolvaptan 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 markedly increases tolvaptan exposure, which may cause excessive aquaresis, dehydration, hypernatremia and overly rapid sodium correction.
How serious is the interaction between Clarithromycin and Tolvaptan?
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 per labeling for strong CYP3A4 inhibitors, or use an alternative antibiotic. If unavoidable, monitor serum sodium and fluid status closely and reduce the tolvaptan dose as labeling advises.
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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