What is the appropriate prescription and dosage for tizepatide (a glucagon-like peptide-1 (GLP-1) receptor agonist) for a patient with type 2 diabetes mellitus, considering their renal function and medical history?

How to Write a Prescription for Tirzepatide 2.5 mg

Prescribe tirzepatide 2.5 mg/0.5 mL subcutaneous injection once weekly, with a quantity of 4 pens (or 4 single-dose vials) for a 28-day supply, starting at the 2.5 mg dose and escalating by 2.5 mg every 4 weeks until the target maintenance dose is achieved. 1

Prescription Format

Drug Name and Strength:

• Tirzepatide 2.5 mg/0.5 mL subcutaneous injection 2

Dosing Instructions:

• Inject 2.5 mg (0.5 mL) subcutaneously once weekly 1
• Administer on the same day each week, at any time of day, with or without meals 2

Quantity:

• Dispense: 4 single-dose prefilled pens (or 4 single-dose vials) 2
• This provides a 28-day supply for once-weekly dosing 1

Refills:

• Specify number of refills based on titration schedule (typically 1 refill for the 2.5 mg starting dose before escalation) 1

Dose Escalation Schedule

Tirzepatide requires a structured titration protocol to minimize gastrointestinal side effects: 1, 3

• Week 0-4: Start at 2.5 mg once weekly 1
• Week 5-8: Increase to 5 mg once weekly 1
• Week 9-12: Increase to 7.5 mg once weekly 1
• Week 13-16: Increase to 10 mg once weekly 1
• Week 17-20: Increase to 12.5 mg once weekly (if needed) 1
• Week 21+: Increase to 15 mg once weekly (if needed for glycemic control) 1

The maintenance dose is typically 5 mg, 10 mg, or 15 mg once weekly, depending on glycemic response and tolerability. 2

Clinical Context and Patient Selection

Tirzepatide is indicated as an adjunct to diet and exercise for adults with type 2 diabetes who have not achieved individualized glycemic targets despite use of metformin and SGLT2 inhibitors, or who are unable to use those medications. 4

Key considerations for prescribing:

• Tirzepatide should be prioritized for patients requiring substantial HbA1c reduction (can achieve 1.87-2.59% reduction) and weight loss (6.2-12.9 kg) 3
• It is particularly appropriate for patients with obesity and type 2 diabetes 4
• Can be used in patients with eGFR ≥30 mL/min/1.73 m² without dose adjustment 4

Important Safety Considerations and Monitoring

Gastrointestinal side effects are the most common adverse events:

• Nausea (13-18%), diarrhea (12-21%), decreased appetite, and vomiting are expected 1, 2
• These are typically mild to moderate and decrease over time with the gradual dose escalation 3
• Starting at 2.5 mg and titrating slowly every 4 weeks minimizes these effects 1

Hypoglycemia risk:

• Low risk when used alone or with metformin 4
• When combined with insulin or sulfonylureas, reduce doses of these agents to prevent hypoglycemia 4

Contraindications and precautions:

• Do not use in combination with DPP-4 inhibitors 4
• Monitor for signs of pancreatitis 2
• Not adequately studied in kidney transplant recipients 4

Sample Prescription

Tirzepatide 2.5 mg/0.5 mL subcutaneous injection
Sig: Inject 2.5 mg (0.5 mL) subcutaneously once weekly on the same day each week
Disp: 4 single-dose prefilled pens
Refills: 1
Instructions: Start with 2.5 mg weekly for 4 weeks, then increase to 5 mg weekly. Patient to follow up for dose titration.

After the initial 4-week period at 2.5 mg, write a new prescription for the next dose (5 mg), continuing this pattern until the maintenance dose is reached. 1