Drug interactions
Haloperidol + Phenelzine
Severity: Moderate
Haloperidol 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
Haloperidol with an MAOI may cause additive hypotension and sedation, and rarely neuroleptic malignant syndrome or serotonin syndrome. Reports are limited, but the consequences can be serious.
What this interaction means in plain words
Haloperidol 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.
Haloperidol belongs to Central Nervous System; Phenelzine belongs to Central Nervous System.
Why it happens
Additive pharmacodynamic effects: dopamine D2 blockade combined with the increased monoamine levels and hypotensive action of MAO inhibition.
What to do
Monitor blood pressure and for fever, rigidity, clonus and altered mental status, especially after initiation or dose increases. Stop one agent if toxicity is suspected.
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 Haloperidol
- Dofetilide + Haloperidol Contraindicated
- Dronedarone + Haloperidol Contraindicated
- Haloperidol + Ibutilide Contraindicated
- Haloperidol + Levoketoconazole Contraindicated
- Haloperidol + Panobinostat Contraindicated
- Haloperidol + Pimozide Contraindicated
Frequently asked questions
Can I take Haloperidol with Phenelzine?
MediHelp rates the interaction as moderate. Haloperidol 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. Haloperidol with an MAOI may cause additive hypotension and sedation, and rarely neuroleptic malignant syndrome or serotonin syndrome. Reports are limited, but the consequences can be serious.
How serious is the interaction between Haloperidol 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 and for fever, rigidity, clonus and altered mental status, especially after initiation or dose increases. Stop one agent if toxicity is suspected.
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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