How to Prescribe Zepbound (Tirzepatide)
Start tirzepatide at 2.5 mg subcutaneously once weekly and titrate monthly to a maintenance dose of 5,10, or 15 mg weekly based on weight loss response and tolerability. 1
Starting Dose and Titration Schedule
Tirzepatide requires a structured dose escalation to minimize gastrointestinal side effects:
- Week 0-4: Start at 2.5 mg subcutaneously once weekly
- Week 5-8: Increase to 5 mg once weekly (this is the minimum maintenance dose)
- Week 9-12: Increase to 7.5 mg once weekly (optional intermediate step) 2
- Week 13-16: Increase to 10 mg once weekly
- Week 17+: Increase to 15 mg once weekly (maximum dose)
The FDA-approved maintenance doses are 5 mg, 10 mg, and 15 mg weekly 1. The 2.5 mg dose is for initiation only, not maintenance. Monthly dose escalation (every 4 weeks) is the standard approach, though slower titration may improve tolerability 2.
FDA-Approved Indications
Tirzepatide (Zepbound) is approved for:
- Chronic weight management in adults with BMI ≥30 kg/m² OR BMI ≥27 kg/m² with at least one weight-related comorbidity 3
- Moderate-to-severe obstructive sleep apnea in adults with obesity 1
Contraindications
Absolute contraindications:
- Personal or family history of medullary thyroid carcinoma 3, 4
- Multiple endocrine neoplasia syndrome type 2 (MEN2) 3, 4
- Pregnancy and breastfeeding 3
Use with caution in:
- History of pancreatitis (consider alternative therapies) 3, 4
- History of cholelithiasis or acute gallbladder disease 3
- Severe renal impairment (risk increases with dehydration from vomiting) 3
- Patients taking insulin or sulfonylureas (increased hypoglycemia risk) 3
Monitoring Requirements
Before initiating:
- Confirm absence of personal/family history of medullary thyroid cancer or MEN2
- Assess for history of pancreatitis
- Document baseline weight and BMI
- Check baseline HbA1c if diabetes or prediabetes present
During treatment:
- Monitor for signs/symptoms of pancreatitis (persistent severe abdominal pain)
- Monitor for acute gallbladder disease
- Watch for severe gastrointestinal adverse events, especially during dose escalation
- Monitor for suicidal ideation and behavior 3
- Assess for hypoglycemia if patient is on insulin or sulfonylureas (dose reduction of these agents may be needed) 3
- No routine calcitonin monitoring is required 4
Expected Outcomes and Response Assessment
Weight loss efficacy:
- At 72 weeks: 15-22.5% mean weight reduction depending on dose (15 mg produces greatest effect) 1, 5
- 85-91% of patients achieve ≥5% weight loss 5
- 50-57% achieve ≥20% weight loss with 10-15 mg doses 1, 5
In patients with type 2 diabetes:
- HbA1c reduction of 1.9-2.2% 1
- Weight loss is somewhat attenuated (12.8-14.7% at 10-15 mg doses) compared to obesity alone 1
Common Side Effects and Management
Most common adverse events are gastrointestinal (occurring primarily during dose escalation) 1, 4:
- Nausea (most common)
- Vomiting
- Diarrhea
- Constipation
- Abdominal pain
Management strategies:
- Use slower dose escalation if GI symptoms are problematic 2
- Lower starting doses (2.5 mg) and smaller increments reduce side effect burden 2
- Most GI symptoms are mild-to-moderate and diminish over time 4
- Consider remaining at current dose longer before escalating if symptoms persist
Discontinuation rates: 4.3-7.1% discontinue due to adverse events 5
Real-World Dosing Patterns
In clinical practice, 84.1% of patients initiate at ≤5 mg dose, and at 6 months, 56.5% remain on doses <10 mg 6. This suggests many patients achieve adequate weight loss without requiring maximum doses. The majority of patients (89.4%) continue treatment at 1 year 7.
Key Clinical Pearls
- Do not combine with GLP-1 receptor agonists (tirzepatide replaces them), but can be combined with SGLT-2 inhibitors 8
- Tirzepatide offers superior weight loss compared to semaglutide 2.4 mg (mean difference 5.1%) and liraglutide 3.0 mg (mean difference 13.0%) 9
- For patients with established cardiovascular disease, consider that GLP-1 RAs have proven CV benefits while tirzepatide's CV outcomes trial is ongoing 8
- Adherence (PDC ≥80%) is 57.5% and persistence is 73.3% at 6 months in real-world settings 6
- Prevents progression from prediabetes to type 2 diabetes (1.3% vs 13.3% with placebo over 176 weeks) 10