Drug interactions
Lithium + Phenelzine
Severity: Major
Lithium and Phenelzine: major 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
Lithium has serotonergic activity, and with an MAO inhibitor there is a risk of serotonin syndrome presenting with agitation, tremor, hyperthermia, clonus and autonomic instability. Lithium toxicity must also be considered.
What this interaction means in plain words
Lithium and Phenelzine 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.
Lithium belongs to Central Nervous System; Phenelzine belongs to Central Nervous System.
Why it happens
Additive serotonergic effects, as lithium enhances serotonin neurotransmission while MAO inhibition reduces serotonin breakdown.
What to do
Avoid the combination where possible and use specialist supervision if both are essential. Monitor for serotonin syndrome symptoms and check serum lithium levels.
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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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 Lithium
- Lithium + Thioridazine Contraindicated
- Lithium + Vandetanib Contraindicated
- Aceclofenac + Lithium Major
- Acemetacin + Lithium Major
- Amisulpride + Lithium Major
- Amlodipine-benazepril + Lithium Major
Frequently asked questions
Can I take Lithium with Phenelzine?
MediHelp rates the interaction as major. Lithium and Phenelzine 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. Lithium has serotonergic activity, and with an MAO inhibitor there is a risk of serotonin syndrome presenting with agitation, tremor, hyperthermia, clonus and autonomic instability. Lithium toxicity must also be considered.
How serious is the interaction between Lithium and Phenelzine?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination where possible and use specialist supervision if both are essential. Monitor for serotonin syndrome symptoms and check serum lithium levels.
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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