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Mounjaro ® (tirzepatide) injection
2.5 mg/5 mg/7.5 mg/10 mg/12.5 mg/15 mg
This information is provided in response to your request. Resources may contain information about doses, uses, formulations and populations different from product labeling. See Prescribing Information above, if applicable.
Can people take Mounjaro® (tirzepatide) with levothyroxine?
Levothyroxine is not contraindicated with the use of tirzepatide; however, tirzepatide delays gastric emptying and thereby has the potential to impact the absorption of concomitantly administered oral medications like levothyroxine.
See important safety information, including boxed warning, in the attached prescribing information.
Use With Levothyroxine
Levothyroxine is not contraindicated with the use of tirzepatide.1
Tirzepatide delays gastric emptying and thereby has the potential to impact the absorption of concomitantly administered oral medications. The impact of tirzepatide on gastric emptying was greatest after a single dose of 5 mg and diminished after subsequent doses.1
Monitor patients on oral medications dependent on threshold concentrations for efficacy and those with a narrow therapeutic index (NTI) when concomitantly administered with tirzepatide.1
The Food and Drug Administration (FDA) has concluded that levothyroxine is a NTI drug.2-4
Eli Lilly and company does not provide specific treatment recommendations. We strongly encourage patients to go to their healthcare provider for treatment advice because they know their patient's medical history the best.
The prescribing information for levothyroxine includes a warning for worsening of diabetic control: Therapy in patients with diabetes mellitus may worsen glycemic control and result in increased antidiabetic agent or insulin requirements. Carefully monitor glycemic control after starting, changing, or discontinuing thyroid hormone therapy.4
Enclosed Prescribing Information
References
1Mounjaro [package insert]. Indianapolis, IN: Eli Lilly and Company; 2023.
2US Food and Drug Administration (FDA). Draft Guidance on Levothyroxine Sodium. Updated December 2014. Accessed August 16, 2023. https://www.accessdata.fda.gov/drugsatfda_docs/psg/Levothyroxine%20sodium_draft_Oral%20tab_RLD%20021116%20%20%20%20%20%20%20%20%20%20%20%20%20%20021210%20%20%20%20%20%20%20%20%20%20%20%20%20%20021301%20%20%20%20%20%20%20%20%20%20%20%20%20%20021342%20%20%20%20%20%20%20%20%20%20%20%20%20%20021402_RC12-14.pdf
3US Food and Drug Administration (FDA). Real-world Evidence from a Narrow Therapeutic Index Product (Levothyroxine) Reflects the Therapeutic Equivalence of Generic Drug Products. Updated November 19, 2020. Accessed August 16, 2023.
4Synthroid [package insert]. North Chicago, IL: AbbVie Inc; 2017.
Date of Last Review: August 14, 2023