Drug interactions
Phenelzine + Phenobarbital
Severity: Moderate
Phenelzine and Phenobarbital: 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
MAO inhibitors have been proposed to prolong the effects of barbiturates such as phenobarbital, producing more sedation. Phenobarbital may also lower seizure threshold changes in the opposite direction, so overall effects are unpredictable. The interaction is mainly theoretical.
What this interaction means in plain words
Phenelzine and Phenobarbital 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
Possible reduced barbiturate metabolism with additive CNS depression; the mechanism is not firmly established.
What to do
Monitor for oversedation and consider checking phenobarbital levels if used for epilepsy. Adjust the dose according to clinical response.
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
Frequently asked questions
Can I take Phenelzine with Phenobarbital?
MediHelp rates the interaction as moderate. Phenelzine and Phenobarbital 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. MAO inhibitors have been proposed to prolong the effects of barbiturates such as phenobarbital, producing more sedation. Phenobarbital may also lower seizure threshold changes in the opposite direction, so overall effects are unpredictable. The interaction is mainly theoretical.
How serious is the interaction between Phenelzine and Phenobarbital?
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 for oversedation and consider checking phenobarbital levels if used for epilepsy. Adjust the dose according to clinical response.
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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