Drug interactions
Amantadine + Olanzapine / samidorphan
Severity: Moderate
Amantadine and Olanzapine / samidorphan: 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
Olanzapine blocks dopamine receptors and may counteract the dopaminergic effects of amantadine, potentially worsening parkinsonism or reducing efficacy. Amantadine may in turn aggravate psychosis in susceptible patients.
What this interaction means in plain words
Amantadine and Olanzapine / samidorphan 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.
Why it happens
Pharmacodynamic antagonism between dopamine receptor blockade by olanzapine and dopaminergic activity of amantadine.
What to do
Monitor motor symptoms and psychiatric status when combining them. Consider a lower-D2-affinity antipsychotic in patients with parkinsonism.
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 Amantadine
- Amantadine + Ethanol Major
- Amantadine + Memantine-donepezil Major
- Amantadine + Metoclopramide Major
- Amantadine + Metoclopramide intranasal Major
- Amantadine + Amifampridine Moderate
- Amantadine + Amisulpride Moderate
Frequently asked questions
Can I take Amantadine with Olanzapine / samidorphan?
MediHelp rates the interaction as moderate. Amantadine and Olanzapine / samidorphan 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. Olanzapine blocks dopamine receptors and may counteract the dopaminergic effects of amantadine, potentially worsening parkinsonism or reducing efficacy. Amantadine may in turn aggravate psychosis in susceptible patients.
How serious is the interaction between Amantadine and Olanzapine / samidorphan?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor motor symptoms and psychiatric status when combining them. Consider a lower-D2-affinity antipsychotic in patients with parkinsonism.
What other medicines interact with Amantadine?
MediHelp also lists interactions of Amantadine with, for example, Ethanol, Memantine-donepezil, Metoclopramide. The full list is on the Amantadine page.
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