Drug interactions
Insulin degludec + Levothyroxine
Severity: Moderate
Insulin degludec and Levothyroxine: 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 glucose production and metabolic demand, so starting or increasing levothyroxine can raise blood glucose in insulin-treated patients. Insulin needs may change as thyroid status is corrected.
What this interaction means in plain words
Insulin degludec and Levothyroxine 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.
Insulin degludec belongs to Endocrine; Levothyroxine belongs to Endocrine.
Why it happens
Thyroid hormones increase gluconeogenesis, glycogen mobilization and glucose turnover, functionally opposing insulin action.
What to do
Monitor blood glucose more frequently when levothyroxine is started, adjusted or stopped. Titrate the insulin degludec dose accordingly.
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 Insulin degludec
Frequently asked questions
Can I take Insulin degludec with Levothyroxine?
MediHelp rates the interaction as moderate. Insulin degludec and Levothyroxine 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 glucose production and metabolic demand, so starting or increasing levothyroxine can raise blood glucose in insulin-treated patients. Insulin needs may change as thyroid status is corrected.
How serious is the interaction between Insulin degludec and Levothyroxine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor blood glucose more frequently when levothyroxine is started, adjusted or stopped. Titrate the insulin degludec dose accordingly.
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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