What precautions should I take before prescribing Mounjaro (tirzepatide) to patients?

Precautions Before Prescribing Mounjaro (Tirzepatide)

Before prescribing Mounjaro (tirzepatide), you must screen patients for contraindications including personal or family history of medullary thyroid carcinoma, multiple endocrine neoplasia syndrome type 2, pregnancy or potential pregnancy, and severe renal impairment.

Key Contraindications

• Thyroid cancer risk: Mounjaro carries a black box warning for risk of thyroid C-cell tumors in rodents (human relevance undetermined) 1
• Pregnancy: Contraindicated in pregnant women or women who may become pregnant 1
• Renal disease: Use with caution due to potential risk of acute kidney injury, particularly when initiating or increasing doses 1

Pre-Prescription Screening Algorithm

1. Medical history assessment:

   • Screen for personal or family history of medullary thyroid carcinoma
   • Screen for multiple endocrine neoplasia syndrome type 2
   • Assess for history of pancreatitis
   • Review history of gallbladder disease

2. Medication review:

   • Check for potential drug interactions
   • For patients on insulin or sulfonylureas, consider dose reduction to prevent hypoglycemia

3. Pregnancy status:

   • Confirm negative pregnancy test in women of reproductive potential
   • Ensure reliable contraception methods are being used

4. Baseline laboratory tests:

   • Renal function (creatinine, eGFR)
   • Liver function tests
   • Fasting blood glucose and HbA1c

Dosing and Titration

Start at the lowest dose (2.5 mg weekly) and titrate gradually:

• Week 1-4: 2.5 mg once weekly
• Week 5-8: 5 mg once weekly
• Week 9-12: 7.5 mg once weekly
• Week 13+: 10 mg once weekly (may increase to 15 mg if needed)

This slow titration minimizes gastrointestinal side effects, which occur in 39-49% of patients 1.

Common Side Effects to Discuss with Patients

• Gastrointestinal effects (most common):
  • Nausea (31%)
  • Diarrhea (23%)
  • Vomiting (12%)
  • Constipation (5%)
  • Abdominal pain (5%) 1

Patient Education Points

1. Injection technique: Proper subcutaneous administration

2. Side effect management:

   • Reducing meal size
   • Limiting alcohol and carbonated drinks
   • Avoiding high-fat diets 1
   • Using antiemetics like ondansetron before dosing if needed
   • Using loperamide for diarrhea if needed

3. When to seek medical attention:

   • Severe abdominal pain (potential pancreatitis)
   • Signs of allergic reaction
   • Persistent vomiting or inability to maintain hydration

Special Considerations

• Surgical procedures: Stop tirzepatide at least one week before elective procedures to minimize aspiration risk due to delayed gastric emptying 1
• Diabetic patients on other medications: Monitor closely for hypoglycemia, especially if on insulin or sulfonylureas
• Gallbladder disease: Tirzepatide may increase risk of cholelithiasis and gallstone-related complications 2

Follow-up Recommendations

• Schedule follow-up 4 weeks after initiation
• Monitor for weight loss and glycemic control
• Assess side effect burden
• Adjust dosage as needed based on efficacy and tolerability

By following these precautions and implementing a structured approach to prescribing Mounjaro, you can maximize benefits while minimizing risks for your patients.