Drug interactions
Cimetidine + Dextroamphetamine
Severity: Minor
Cimetidine and Dextroamphetamine: 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 might slightly raise amphetamine exposure by reducing its metabolism, though the effect is poorly characterized. Stimulant adverse effects could be mildly increased.
What this interaction means in plain words
Cimetidine and Dextroamphetamine 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 belongs to Gastrointestinal Tract; Dextroamphetamine belongs to Central Nervous System.
Why it happens
Cimetidine may inhibit CYP2D6-mediated amphetamine metabolism; the mechanism is not firmly established.
What to do
No dose change is routinely needed; monitor heart rate, blood pressure and agitation after starting cimetidine.
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 Dextroamphetamine
- Dextroamphetamine + Isocarboxazid Contraindicated
- Dextroamphetamine + Linezolid Contraindicated
- Dextroamphetamine + Methylene blue Contraindicated
- Dextroamphetamine + Phenelzine Contraindicated
- Dextroamphetamine + Rasagiline Contraindicated
- Dextroamphetamine + Safinamide Contraindicated
Frequently asked questions
Can I take Cimetidine with Dextroamphetamine?
MediHelp rates the interaction as minor. Cimetidine and Dextroamphetamine 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 might slightly raise amphetamine exposure by reducing its metabolism, though the effect is poorly characterized. Stimulant adverse effects could be mildly increased.
How serious is the interaction between Cimetidine and Dextroamphetamine?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No dose change is routinely needed; monitor heart rate, blood pressure and agitation after starting cimetidine.
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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