Drug interactions
Clarithromycin + Salmeterol
Severity: Major
Clarithromycin and Salmeterol: 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
Clarithromycin strongly inhibits CYP3A4 and can markedly raise systemic salmeterol exposure. This increases beta-agonist cardiovascular effects such as tachycardia, tremor, hypokalemia and QT prolongation, and clarithromycin itself prolongs the QT interval.
What this interaction means in plain words
Clarithromycin and Salmeterol 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; Salmeterol belongs to Respiratory.
Why it happens
Inhibition of CYP3A4-mediated salmeterol metabolism by clarithromycin, with additive QT prolongation.
What to do
Avoid the combination where possible and choose an alternative antibiotic such as azithromycin with less CYP3A4 effect, or a non-interacting agent. If it cannot be avoided, monitor ECG, heart rate and potassium.
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 Salmeterol
- Ritonavir + Salmeterol Contraindicated
- Salmeterol + Saquinavir Contraindicated
- Amitriptyline + Salmeterol Major
- Arformoterol + Salmeterol Major
- Atazanavir + Salmeterol Major
- Budesonide-formoterol + Salmeterol Major
Other interactions of Clarithromycin
- Astemizole + Clarithromycin Contraindicated
- Avanafil + Clarithromycin Contraindicated
- Cisapride + Clarithromycin Contraindicated
- Clarithromycin + Colchicine Contraindicated
- Clarithromycin + Conivaptan Contraindicated
- Clarithromycin + Dihydroergotamine Contraindicated
Frequently asked questions
Can I take Clarithromycin with Salmeterol?
MediHelp rates the interaction as major. Clarithromycin and Salmeterol 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 strongly inhibits CYP3A4 and can markedly raise systemic salmeterol exposure. This increases beta-agonist cardiovascular effects such as tachycardia, tremor, hypokalemia and QT prolongation, and clarithromycin itself prolongs the QT interval.
How serious is the interaction between Clarithromycin and Salmeterol?
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 where possible and choose an alternative antibiotic such as azithromycin with less CYP3A4 effect, or a non-interacting agent. If it cannot be avoided, monitor ECG, heart rate and potassium.
What other medicines interact with Salmeterol?
MediHelp also lists interactions of Salmeterol with, for example, Ritonavir, Saquinavir, Amitriptyline. The full list is on the Salmeterol page.
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