Drug interactions
Olanzapine + Phenelzine
Severity: Moderate
Olanzapine and Phenelzine: 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
Phenelzine with olanzapine may produce additive hypotension and sedation. Rare cases of serotonin toxicity or neuroleptic malignant syndrome are possible because monoamine levels are raised while dopamine receptors are blocked.
What this interaction means in plain words
Olanzapine and Phenelzine 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 belongs to Central Nervous System; Phenelzine belongs to Central Nervous System.
Why it happens
Additive pharmacodynamic effects of MAO inhibition (increased monoamines) with D2 and 5-HT2A receptor antagonism and alpha-1 blockade.
What to do
Monitor blood pressure, mental status, temperature and muscle tone when starting or adjusting either drug. Stop the antipsychotic and treat urgently if features of serotonin toxicity or neuroleptic malignant syndrome develop.
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 Phenelzine
- 5-HTP + Phenelzine Contraindicated
- Amitriptyline + Phenelzine Contraindicated
- Amoxapine + Phenelzine Contraindicated
- Atomoxetine + Phenelzine Contraindicated
- Benzphetamine + Phenelzine Contraindicated
- Brimonidine + Phenelzine Contraindicated
Other interactions of Olanzapine
Frequently asked questions
Can I take Olanzapine with Phenelzine?
MediHelp rates the interaction as moderate. Olanzapine and Phenelzine 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. Phenelzine with olanzapine may produce additive hypotension and sedation. Rare cases of serotonin toxicity or neuroleptic malignant syndrome are possible because monoamine levels are raised while dopamine receptors are blocked.
How serious is the interaction between Olanzapine and Phenelzine?
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 blood pressure, mental status, temperature and muscle tone when starting or adjusting either drug. Stop the antipsychotic and treat urgently if features of serotonin toxicity or neuroleptic malignant syndrome develop.
What other medicines interact with Phenelzine?
MediHelp also lists interactions of Phenelzine with, for example, 5-HTP, Amitriptyline, Amoxapine. The full list is on the Phenelzine page.
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