From the Guidelines
Mounjaro (tirzepatide) is not FDA-approved for type 1 diabetes management and should not be used as a replacement for insulin therapy in these patients. Type 1 diabetes patients lack the ability to produce insulin naturally and should continue using insulin as their primary treatment. While Mounjaro has shown effectiveness for type 2 diabetes by improving insulin sensitivity and reducing blood glucose levels through its dual GIP and GLP-1 receptor agonist action, its use in type 1 diabetes is not established. Some endocrinologists may occasionally prescribe Mounjaro off-label as an adjunct therapy to help reduce insulin requirements or improve glucose control in select type 1 diabetes patients, but this should only be done under close medical supervision 1.
The typical starting dose for Mounjaro in type 2 diabetes is 2.5 mg weekly by subcutaneous injection, gradually increasing to a maintenance dose of 5-15 mg weekly, but these dosing guidelines have not been established for type 1 diabetes. Type 1 diabetes patients interested in Mounjaro should discuss this option with their endocrinologist to evaluate potential benefits versus risks, including the possibility of diabetic ketoacidosis if insulin therapy is reduced inappropriately.
Key considerations for type 1 diabetes management include:
- Insulin therapy as the primary treatment
- Potential use of adjunct therapies like pramlintide to enhance satiety and reduce prandial insulin dosing
- Close monitoring of blood glucose levels and adjustment of insulin doses as needed
- Lifestyle modifications, such as diet and exercise, to optimize glucose control
- Regular evaluation of potential benefits and risks of any medication, including Mounjaro, in the context of individual patient needs and medical history 1.
It is essential to prioritize the use of established, FDA-approved treatments for type 1 diabetes and to approach off-label use of medications like Mounjaro with caution, considering the potential risks and benefits in the context of individual patient care 1.
From the FDA Drug Label
MOUNJARO is an injectable prescription medicine that is used along with diet and exercise to improve blood sugar (glucose) in adults with type 2 diabetes mellitus. MOUNJARO is not for use in people with type 1 diabetes.
Mounjaro is not indicated for use in patients with type 1 diabetes mellitus 2.
From the Research
Mounjaro and Type 1 Diabetes
- Mounjaro (tirzepatide) is approved for the management of type 2 diabetes, but its efficacy and safety in type 1 diabetes have also been studied 3.
- A proof of concept observational study found that tirzepatide significantly reduced HbA1c and body weight in adults with type 1 diabetes, with a mean reduction in HbA1c of 0.45% at 3 months and 0.59% at 8 months 3.
- The study also found that tirzepatide improved continuous glucose monitoring (CGM) metrics, including time in target range and time in tight target range, and reduced time above range 3.
Safety and Tolerability
- Tirzepatide was generally well tolerated in the study, with only 2 patients discontinuing the medication due to adverse events 3.
- The most common adverse events associated with tirzepatide were gastrointestinal events, including nausea, diarrhea, decreased appetite, and vomiting 4, 5, 6.
Comparison to Other Treatments
- Tirzepatide has been shown to be more effective than selective GLP-1 receptor agonists, such as semaglutide, in reducing HbA1c and body weight in type 2 diabetes 5, 6.
- However, its efficacy and safety in type 1 diabetes need to be further established through randomized controlled trials 3.