Drug interactions
Lithium + Protriptyline
Severity: Moderate
Lithium and Protriptyline: 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
Lithium has serotonergic effects, and combining it with a tricyclic antidepressant may rarely lead to serotonin syndrome. Both agents can also prolong the QT interval and lithium may increase tricyclic-related neurotoxicity.
What this interaction means in plain words
Lithium and Protriptyline 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
Additive serotonergic activity and additive effects on cardiac repolarization.
What to do
Monitor for agitation, tremor, hyperreflexia, sweating and fever, particularly when starting or increasing doses. Check an ECG when there are cardiac risk factors and monitor lithium levels.
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 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 Protriptyline?
MediHelp rates the interaction as moderate. Lithium and Protriptyline 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. Lithium has serotonergic effects, and combining it with a tricyclic antidepressant may rarely lead to serotonin syndrome. Both agents can also prolong the QT interval and lithium may increase tricyclic-related neurotoxicity.
How serious is the interaction between Lithium and Protriptyline?
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 agitation, tremor, hyperreflexia, sweating and fever, particularly when starting or increasing doses. Check an ECG when there are cardiac risk factors and monitor lithium levels.
What other medicines interact with Lithium?
MediHelp also lists interactions of Lithium with, for example, Thioridazine, Vandetanib, Aceclofenac. The full list is on the Lithium page.
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