Drug interactions
Amitriptyline + L-tryptophan
Severity: Moderate
Amitriptyline 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
Tryptophan is a serotonin precursor, and amitriptyline inhibits serotonin reuptake, so the combination can increase serotonergic activity. Serotonin syndrome has been described with tryptophan and antidepressants, though most reports involve higher-risk combinations.
What this interaction means in plain words
Amitriptyline 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 inhibition of serotonin reuptake by amitriptyline.
What to do
Avoid high-dose tryptophan supplementation with amitriptyline. Monitor for agitation, tremor, diaphoresis, hyperreflexia and hyperthermia, and stop tryptophan if serotonin 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 Amitriptyline
- Amitriptyline + Isocarboxazid Contraindicated
- Amitriptyline + Methylene blue Contraindicated
- Amitriptyline + Phenelzine Contraindicated
- Amitriptyline + Pimozide Contraindicated
- Amitriptyline + Procarbazine Contraindicated
- Amitriptyline + Safinamide Contraindicated
Frequently asked questions
Can I take Amitriptyline with L-tryptophan?
MediHelp rates the interaction as moderate. Amitriptyline 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. Tryptophan is a serotonin precursor, and amitriptyline inhibits serotonin reuptake, so the combination can increase serotonergic activity. Serotonin syndrome has been described with tryptophan and antidepressants, though most reports involve higher-risk combinations.
How serious is the interaction between Amitriptyline 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 high-dose tryptophan supplementation with amitriptyline. Monitor for agitation, tremor, diaphoresis, hyperreflexia and hyperthermia, and stop tryptophan if serotonin toxicity is suspected.
What other medicines interact with Amitriptyline?
MediHelp also lists interactions of Amitriptyline with, for example, Isocarboxazid, Methylene blue, Phenelzine. The full list is on the Amitriptyline page.
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