Drug interactions
Clarithromycin + Doxepin
Severity: Moderate
Clarithromycin and Doxepin: moderate 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
Both drugs can prolong the QT interval, and clarithromycin may raise doxepin concentrations. This can increase the risk of arrhythmia, particularly with other risk factors, and of anticholinergic and sedative effects.
What this interaction means in plain words
Clarithromycin and Doxepin can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Clarithromycin belongs to Anti Bacterial; Doxepin belongs to Dermatology.
Why it happens
Additive QT prolongation, with possible CYP2D6/CYP3A4-related reduction in doxepin clearance by clarithromycin.
What to do
Consider azithromycin or another non-macrolide antibiotic. If co-administered, check baseline QTc and electrolytes and monitor for arrhythmia symptoms and excess sedation.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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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 Doxepin
- Doxepin + Isocarboxazid Contraindicated
- Doxepin + Phenelzine Contraindicated
- Doxepin + Procarbazine Contraindicated
- Doxepin + Safinamide Contraindicated
- Doxepin + Selegiline Contraindicated
- Doxepin + Tranylcypromine Contraindicated
Frequently asked questions
Can I take Clarithromycin with Doxepin?
MediHelp rates the interaction as moderate. Clarithromycin and Doxepin can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Both drugs can prolong the QT interval, and clarithromycin may raise doxepin concentrations. This can increase the risk of arrhythmia, particularly with other risk factors, and of anticholinergic and sedative effects.
How serious is the interaction between Clarithromycin and Doxepin?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Consider azithromycin or another non-macrolide antibiotic. If co-administered, check baseline QTc and electrolytes and monitor for arrhythmia symptoms and excess sedation.
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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