Drug interactions
Levothyroxine + Trimagnesium
Severity: Moderate
Levothyroxine and Trimagnesium: 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
Oral magnesium salts can bind levothyroxine in the gut and decrease its absorption. This may raise TSH and reduce control of hypothyroidism.
What this interaction means in plain words
Levothyroxine and Trimagnesium 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
Magnesium binds levothyroxine in the gut lumen and may raise gastric pH, reducing absorption.
What to do
Take levothyroxine at least 4 hours before or after the magnesium product. Check TSH about 6 to 8 weeks after any change in magnesium use.
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 Levothyroxine
Frequently asked questions
Can I take Levothyroxine with Trimagnesium?
MediHelp rates the interaction as moderate. Levothyroxine and Trimagnesium 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. Oral magnesium salts can bind levothyroxine in the gut and decrease its absorption. This may raise TSH and reduce control of hypothyroidism.
How serious is the interaction between Levothyroxine and Trimagnesium?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Take levothyroxine at least 4 hours before or after the magnesium product. Check TSH about 6 to 8 weeks after any change in magnesium use.
What other medicines interact with Levothyroxine?
MediHelp also lists interactions of Levothyroxine with, for example, Cholestyramine, Sodium iodide i-131, Tiratricol. The full list is on the Levothyroxine page.
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