Drug interactions
Carbidopa-entacapone-levodopa + Olanzapine
Severity: Major
Carbidopa-entacapone-levodopa and Olanzapine: major interaction.
Last updated Sources: US FDA label
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 can reduce the benefit of levodopa, worsening parkinsonian motor symptoms. The effect is dose related and may be clinically significant in patients with Parkinson disease.
What this interaction means in plain words
Carbidopa-entacapone-levodopa and Olanzapine 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.
Carbidopa-entacapone-levodopa belongs to Central Nervous System; Olanzapine belongs to Central Nervous System.
Why it happens
Pharmacodynamic antagonism through D2 receptor blockade opposing levodopa-derived dopamine.
What to do
Prefer quetiapine, clozapine or pimavanserin for psychosis in Parkinson disease. If olanzapine must be used, give the lowest dose and monitor motor function.
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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References
Other interactions of Carbidopa-entacapone-levodopa
- Carbidopa-entacapone-levodopa + Isocarboxazid Contraindicated
- Carbidopa-entacapone-levodopa + Phenelzine Contraindicated
- Carbidopa-entacapone-levodopa + Selegiline transdermal Contraindicated
- Carbidopa-entacapone-levodopa + Tranylcypromine Contraindicated
- Amisulpride + Carbidopa-entacapone-levodopa Major
- Asenapine transdermal + Carbidopa-entacapone-levodopa Major
Other interactions of Olanzapine
Frequently asked questions
Can I take Carbidopa-entacapone-levodopa with Olanzapine?
MediHelp rates the interaction as major. Carbidopa-entacapone-levodopa and Olanzapine 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. Olanzapine blocks dopamine receptors and can reduce the benefit of levodopa, worsening parkinsonian motor symptoms. The effect is dose related and may be clinically significant in patients with Parkinson disease.
How serious is the interaction between Carbidopa-entacapone-levodopa and Olanzapine?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Prefer quetiapine, clozapine or pimavanserin for psychosis in Parkinson disease. If olanzapine must be used, give the lowest dose and monitor motor function.
What other medicines interact with Carbidopa-entacapone-levodopa?
MediHelp also lists interactions of Carbidopa-entacapone-levodopa with, for example, Isocarboxazid, Phenelzine, Selegiline transdermal. The full list is on the Carbidopa-entacapone-levodopa page.
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