What should I do if I experience an allergic reaction to Mounjaro (tirzepatide)?

Management of Allergic Reaction to Mounjaro (Tirzepatide)

If you experience an allergic reaction to Mounjaro (tirzepatide), seek immediate medical attention and administer epinephrine via auto-injector for severe reactions involving breathing difficulty, significant swelling, or hypotension.

Recognizing an Allergic Reaction to Mounjaro

Allergic reactions to Mounjaro can range from mild to severe. It's important to identify the symptoms quickly:

Mild to Moderate Reactions

• Skin reactions: rash, hives, itching
• Mild swelling (especially of face, lips, or tongue)
• Gastrointestinal symptoms: nausea, vomiting
• Respiratory symptoms: mild shortness of breath

Severe Reactions (Anaphylaxis)

• Difficulty breathing or swallowing
• Significant drop in blood pressure
• Severe swelling of face, lips, tongue
• Dizziness or loss of consciousness
• Rapid heartbeat

Emergency Management Algorithm

For Severe Reactions (Anaphylaxis)

1. Administer epinephrine immediately using an auto-injector if available 1

   • Adult dose: 0.3-0.5 mg intramuscularly in the mid-outer thigh
   • Can repeat every 5-15 minutes if symptoms persist

2. Call emergency services (911) or have someone take you to the nearest emergency department

3. Position yourself appropriately

   • If experiencing difficulty breathing: sit upright
   • If feeling faint: lie flat with legs elevated 1

4. Additional emergency measures (to be administered by healthcare professionals):

   • Oxygen supplementation if hypoxic
   • IV fluids for hypotension
   • Additional medications as needed (antihistamines, corticosteroids) 1

For Mild to Moderate Reactions

1. Take an oral antihistamine (such as diphenhydramine/Benadryl)

2. Monitor symptoms closely for at least 4-6 hours 1

   • If symptoms worsen or don't improve, seek medical attention

3. Contact your healthcare provider to report the reaction

Follow-up Care

After experiencing an allergic reaction to Mounjaro:

1. Schedule an appointment with your healthcare provider within 1-2 weeks 1

2. Consider referral to an allergist for evaluation, especially after moderate to severe reactions 1

3. Medication adjustments:

   • Your provider will likely discontinue Mounjaro
   • Alternative medications for diabetes or weight management will be considered

4. Emergency preparedness:

   • Obtain an epinephrine auto-injector prescription
   • Create an emergency action plan 1
   • Consider medical identification jewelry indicating your allergy

Important Considerations

• Tirzepatide is a dual GIP/GLP-1 receptor agonist with common side effects including gastrointestinal symptoms that should not be confused with allergic reactions 2, 3

• Cross-reactivity: If you've had an allergic reaction to Mounjaro, discuss with your doctor the potential for cross-reactivity with other GLP-1 receptor agonists like semaglutide 4

• Documentation: Keep detailed records of your reaction symptoms, timing, and treatment response to share with healthcare providers

Prevention

If you've experienced a true allergic reaction to Mounjaro:

• The medication should not be used again, especially if the reaction was severe 1

• Alternatives: Your healthcare provider can recommend alternative medications for managing diabetes or weight 1

• Desensitization is generally not recommended for severe drug allergic reactions to Mounjaro 1

Remember that true allergic reactions to Mounjaro are different from common side effects. Gastrointestinal symptoms like nausea, vomiting, and diarrhea are expected side effects of the medication and not necessarily allergic reactions 4, 3.