Drug interactions
Duloxetine + L-tryptophan
Severity: Moderate
Duloxetine and L-tryptophan: 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
L-tryptophan is the precursor of serotonin, and giving it with a serotonin reuptake inhibitor can increase serotonergic activity. Case reports describe serotonin syndrome with agitation, tremor and hyperthermia with antidepressant combinations.
What this interaction means in plain words
Duloxetine and L-tryptophan 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
Increased serotonin synthesis from tryptophan combined with reuptake inhibition by duloxetine.
What to do
Avoid unsupervised use of tryptophan supplements with duloxetine. If combined, use low doses and monitor for signs of serotonin syndrome.
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 Duloxetine
- Duloxetine + Isocarboxazid Contraindicated
- Duloxetine + Linezolid Contraindicated
- Duloxetine + Methylene blue Contraindicated
- Duloxetine + Phenelzine Contraindicated
- Duloxetine + Procarbazine Contraindicated
- Duloxetine + Rasagiline Contraindicated
Frequently asked questions
Can I take Duloxetine with L-tryptophan?
MediHelp rates the interaction as moderate. Duloxetine and L-tryptophan 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. L-tryptophan is the precursor of serotonin, and giving it with a serotonin reuptake inhibitor can increase serotonergic activity. Case reports describe serotonin syndrome with agitation, tremor and hyperthermia with antidepressant combinations.
How serious is the interaction between Duloxetine and L-tryptophan?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid unsupervised use of tryptophan supplements with duloxetine. If combined, use low doses and monitor for signs of serotonin syndrome.
What other medicines interact with Duloxetine?
MediHelp also lists interactions of Duloxetine with, for example, Isocarboxazid, Linezolid, Methylene blue. The full list is on the Duloxetine page.
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