What are the causes of tirzepatide (Mounjaro)-induced diarrhea?

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From the Guidelines

Mounjaro-induced diarrhea is a common side effect that can be managed with hydration, dietary changes, and over-the-counter medications like loperamide. To manage this side effect, patients can start by staying well-hydrated and consuming smaller, more frequent meals that are low in fat and fiber. Over-the-counter medications like loperamide (Imodium) at standard dosing (2mg after each loose stool, not exceeding 8mg per day) can help control symptoms, as suggested by general clinical guidelines 1. If diarrhea is severe or persistent, contact your healthcare provider, as they may recommend temporarily reducing your Mounjaro dose or adjusting the injection schedule. Most patients find that diarrhea improves over time as the body adjusts to the medication. This side effect occurs because Mounjaro, as a glucagon-like peptide-1 receptor agonist, affects gut motility and slows gastric emptying while also influencing the gut microbiome, as described in the narrative review of clinical pharmacology 1. Key considerations for managing Mounjaro-induced diarrhea include:

  • Staying hydrated to prevent dehydration
  • Eating smaller, more frequent meals to reduce symptom severity
  • Using over-the-counter medications like loperamide to control symptoms
  • Contacting a healthcare provider if symptoms are severe or persistent
  • Being aware of potential complications like severe abdominal pain, fever, or blood in stool, which require immediate medical attention.

From the FDA Drug Label

MOUNJARO may cause serious side effects, including: ... severe stomach problems. Stomach problems, sometimes severe, have been reported in people who use MOUNJARO ... The most common side effects of MOUNJARO include: nausea diarrhea decreased appetite vomiting constipation indigestion stomach (abdominal) pain MOUNJARO has been associated with gastrointestinal adverse reactions, which include nausea, vomiting, and diarrhea [see Adverse Reactions (6. 1)]. Use of MOUNJARO has been associated with gastrointestinal adverse reactions, sometimes severe [see Adverse Reactions 6.1].

Mounjaro-induced diarrhea is a possible side effect of the medication. According to the drug label, diarrhea is one of the most common side effects of MOUNJARO, and it can be severe in some cases. Patients taking MOUNJARO should be monitored for signs and symptoms of gastrointestinal adverse reactions, including diarrhea. If diarrhea occurs, patients should inform their healthcare provider, who can provide guidance on managing the symptom. 2 2 2

From the Research

Mounjaro-Induced Diarrhea

  • Mounjaro, also known as tirzepatide, is a dual GIP and GLP-1 receptor agonist used for the treatment of type 2 diabetes and obesity.
  • According to a study published in 2024 3, 13.2% of participants developed gastrointestinal events, including diarrhea, when switched to tirzepatide 5 mg from GLP-1 receptor agonists.
  • Another study published in 2024 4 found that tirzepatide was associated with a lower risk of adverse gastrointestinal events compared to GLP-1 receptor agonists.
  • However, the exact incidence of diarrhea induced by Mounjaro is not explicitly stated in the provided studies.
  • It is worth noting that tirzepatide has been shown to have beneficial effects on glucose metabolism, weight reduction, and cardiovascular risk profiles 5, 4, 6, 7.
  • Further research is needed to fully understand the gastrointestinal side effects of Mounjaro, including diarrhea.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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