Drug interactions
Levothyroxine + Nortriptyline
Severity: Moderate
Levothyroxine and Nortriptyline: 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
Thyroid hormone increases adrenergic sensitivity and may enhance the effects of tricyclics. Cardiac arrhythmias and CNS stimulation have been reported, especially with supraphysiologic thyroid doses.
What this interaction means in plain words
Levothyroxine and Nortriptyline 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.
Levothyroxine belongs to Endocrine; Nortriptyline belongs to Central Nervous System.
Why it happens
Increased catecholamine receptor sensitivity from thyroid hormone, with possible changes in tricyclic response.
What to do
Maintain euthyroid dosing and monitor heart rate, rhythm and mood after changes in thyroid dose. Reduce either dose if arrhythmia or agitation develops.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Levothyroxine and Nortriptyline, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 14 days on the web. No card needed.
Other interactions of Nortriptyline
- Disopyramide + Nortriptyline Contraindicated
- Dofetilide + Nortriptyline Contraindicated
- Dronedarone + Nortriptyline Contraindicated
- Ibutilide + Nortriptyline Contraindicated
- Isocarboxazid + Nortriptyline Contraindicated
- Methylene blue + Nortriptyline Contraindicated
Other interactions of Levothyroxine
Frequently asked questions
Can I take Levothyroxine with Nortriptyline?
MediHelp rates the interaction as moderate. Levothyroxine and Nortriptyline 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. Thyroid hormone increases adrenergic sensitivity and may enhance the effects of tricyclics. Cardiac arrhythmias and CNS stimulation have been reported, especially with supraphysiologic thyroid doses.
How serious is the interaction between Levothyroxine and Nortriptyline?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Maintain euthyroid dosing and monitor heart rate, rhythm and mood after changes in thyroid dose. Reduce either dose if arrhythmia or agitation develops.
What other medicines interact with Nortriptyline?
MediHelp also lists interactions of Nortriptyline with, for example, Disopyramide, Dofetilide, Dronedarone. The full list is on the Nortriptyline page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
