Drug interactions
Atomoxetine + Cimetidine
Severity: Minor
Atomoxetine and Cimetidine: minor 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
Cimetidine is a weak CYP2D6 inhibitor and may raise atomoxetine levels, which are strongly dependent on CYP2D6. This may increase heart rate, blood pressure, and adverse effects such as insomnia or nausea.
What this interaction means in plain words
Atomoxetine and Cimetidine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Atomoxetine belongs to Central Nervous System; Cimetidine belongs to Gastrointestinal Tract.
Why it happens
Cimetidine inhibits CYP2D6-mediated metabolism of atomoxetine.
What to do
Monitor heart rate, blood pressure and tolerability. Adjust the atomoxetine dose if adverse effects emerge.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Cimetidine
- Cimetidine + Dofetilide Contraindicated
- Cimetidine + Fezolinetant Contraindicated
- Alfentanil + Cimetidine Major
- Atazanavir + Cimetidine Major
- Carmustine + Cimetidine Major
- Cimetidine + Citalopram Major
Other interactions of Atomoxetine
- Atomoxetine + Isocarboxazid Contraindicated
- Atomoxetine + Linezolid Contraindicated
- Atomoxetine + Phenelzine Contraindicated
- Atomoxetine + Procarbazine Contraindicated
- Atomoxetine + Rasagiline Contraindicated
- Atomoxetine + Selegiline Contraindicated
Frequently asked questions
Can I take Atomoxetine with Cimetidine?
MediHelp rates the interaction as minor. Atomoxetine and Cimetidine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Cimetidine is a weak CYP2D6 inhibitor and may raise atomoxetine levels, which are strongly dependent on CYP2D6. This may increase heart rate, blood pressure, and adverse effects such as insomnia or nausea.
How serious is the interaction between Atomoxetine and Cimetidine?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor heart rate, blood pressure and tolerability. Adjust the atomoxetine dose if adverse effects emerge.
What other medicines interact with Cimetidine?
MediHelp also lists interactions of Cimetidine with, for example, Dofetilide, Fezolinetant, Alfentanil. The full list is on the Cimetidine page.
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