Drug interactions
Levothyroxine + Orlistat
Severity: Moderate
Levothyroxine and Orlistat: 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
Orlistat has been associated with hypothyroidism in patients on levothyroxine, with raised TSH after the drug was added. Reduced absorption of levothyroxine is the proposed cause.
What this interaction means in plain words
Levothyroxine and Orlistat 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; Orlistat belongs to Miscellaneous.
Why it happens
Orlistat may reduce levothyroxine absorption, possibly through binding or altered intestinal lipid handling; the mechanism is not fully established.
What to do
Take levothyroxine at least 4 hours apart from orlistat. Check TSH after starting or stopping orlistat and adjust the dose as needed.
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
Other interactions of Orlistat
- Cyclosporine + Orlistat Major
- Cyclosporin + Orlistat Major
- Orlistat + Triheptanoin Major
- Amiodarone + Orlistat Moderate
- Beta carotene + Orlistat Moderate
- Carbamazepine + Orlistat Moderate
Frequently asked questions
Can I take Levothyroxine with Orlistat?
MediHelp rates the interaction as moderate. Levothyroxine and Orlistat 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. Orlistat has been associated with hypothyroidism in patients on levothyroxine, with raised TSH after the drug was added. Reduced absorption of levothyroxine is the proposed cause.
How serious is the interaction between Levothyroxine and Orlistat?
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 apart from orlistat. Check TSH after starting or stopping orlistat and adjust the dose as needed.
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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