Drug interactions
Amitriptyline + Erythromycin lactobionate
Severity: Major
Amitriptyline and Erythromycin lactobionate: 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
Intravenous erythromycin can raise amitriptyline concentrations and both drugs prolong the QT interval. This increases the risk of anticholinergic toxicity and torsades de pointes.
What this interaction means in plain words
Amitriptyline and Erythromycin lactobionate 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.
Amitriptyline belongs to Central Nervous System; Erythromycin lactobionate belongs to Anti Bacterial.
Why it happens
CYP3A4 inhibition by erythromycin reduces amitriptyline clearance, with additive QT prolongation.
What to do
Choose a non-macrolide alternative where possible, or monitor ECG and electrolytes closely. Consider holding or reducing amitriptyline during therapy.
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 Amitriptyline
- Amitriptyline + Isocarboxazid Contraindicated
- Amitriptyline + Methylene blue Contraindicated
- Amitriptyline + Phenelzine Contraindicated
- Amitriptyline + Pimozide Contraindicated
- Amitriptyline + Procarbazine Contraindicated
- Amitriptyline + Safinamide Contraindicated
Other interactions of Erythromycin lactobionate
- Cisapride + Erythromycin lactobionate Contraindicated
- Dihydroergotamine + Erythromycin lactobionate Contraindicated
- Dronedarone + Erythromycin lactobionate Contraindicated
- Eletriptan + Erythromycin lactobionate Contraindicated
- Ergotamine + Erythromycin lactobionate Contraindicated
- Erythromycin lactobionate + Flibanserin Contraindicated
Frequently asked questions
Can I take Amitriptyline with Erythromycin lactobionate?
MediHelp rates the interaction as major. Amitriptyline and Erythromycin lactobionate 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. Intravenous erythromycin can raise amitriptyline concentrations and both drugs prolong the QT interval. This increases the risk of anticholinergic toxicity and torsades de pointes.
How serious is the interaction between Amitriptyline and Erythromycin lactobionate?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Choose a non-macrolide alternative where possible, or monitor ECG and electrolytes closely. Consider holding or reducing amitriptyline during therapy.
What other medicines interact with Amitriptyline?
MediHelp also lists interactions of Amitriptyline with, for example, Isocarboxazid, Methylene blue, Phenelzine. The full list is on the Amitriptyline page.
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