What pre-treatment labs or testing are recommended before starting GLP-1 (Glucagon-Like Peptide-1) receptor agonists like liraglutide (Victoza) or semaglutide (Ozempic) for weight loss management?

Pre-Treatment Labs and Monitoring for GLP-1 Receptor Agonists

No specific pre-treatment laboratory tests are universally required before initiating GLP-1 receptor agonists for weight management, but documentation of baseline weight, BMI, and assessment of comorbidities is essential for proper patient selection and monitoring. 1

Patient Selection and Documentation

• Document baseline measurements including weight, BMI, and waist circumference to establish eligibility (BMI ≥30 kg/m² or BMI ≥27 kg/m² with weight-related comorbidities) 1
• Record indication for GLP-1 receptor agonist therapy (weight management, diabetes, or both) 2
• Document relevant comorbidities that may benefit from GLP-1 therapy, such as:
  • Pre-diabetes or diabetes status 1
  • Cardiovascular disease risk factors 1
  • Non-alcoholic fatty liver disease 2
  • History of gestational diabetes 1

Recommended Baseline Assessments

• Medical History Assessment:

  • Document history of pancreatitis, gallbladder disease, or thyroid conditions 2
  • Assess for medications that may delay gastric emptying (opioids, proton pump inhibitors, tricyclic antidepressants) 2
  • Document previous gastrointestinal surgeries 2
  • Screen for symptoms of gastroparesis or gastrointestinal disorders 2

• Laboratory Testing:

  • Basic metabolic panel to assess kidney function 3
  • Liver function tests, especially if patient has risk factors for liver disease 2
  • HbA1c for patients with pre-diabetes or diabetes 2
  • Consider thyroid function tests as baseline (though not specifically required) 2

Monitoring Recommendations

• Efficacy Monitoring:

  • Weight should be measured at baseline and regularly during treatment 1
  • Set weight loss goal of at least 5% at 12 weeks for continued therapy 1
  • For patients with diabetes, monitor blood glucose and HbA1c 2

• Safety Monitoring:

  • Monitor for gastrointestinal side effects (nausea, vomiting, abdominal pain) 2
  • Assess for signs of pancreatitis or gallbladder disease 2
  • For diabetic patients, monitor for hypoglycemia, especially if on insulin or insulin secretagogues 2

Special Considerations

• Perioperative Management:

  • For patients scheduled for surgery, document:
    • Type, dose, and duration of GLP-1 therapy 2
    • Last dose taken 2
    • Consider holding GLP-1 receptor agonist for at least three half-lives before elective procedures (approximately 3 weeks for semaglutide) 2
    • For patients taking GLP-1 for diabetes, consult with endocrinologist regarding perioperative management 2

• Dose Titration:

  • Document baseline dose and planned titration schedule 2
  • For semaglutide: Start at 0.25 mg weekly for 4 weeks, followed by 0.5 mg, 1.0 mg, and 1.7 mg weekly every 4 weeks until reaching maintenance dose of 2.4 mg 2
  • For liraglutide: Start with 0.6 mg daily for 7 days, followed by 1.2 mg, 1.8 mg, and 2.4 mg daily every 7 days until reaching maintenance dose of 3.0 mg 2

Common Pitfalls to Avoid

• Failure to distinguish between weight management and diabetes indications:

  • Different monitoring approaches may be needed depending on indication 2
  • Higher doses are typically used for weight management (semaglutide 2.4 mg weekly, liraglutide 3.0 mg daily) 2

• Inadequate monitoring of diabetic patients:

  • Patients on insulin or insulin secretagogues may need dose adjustments to prevent hypoglycemia 2
  • GLP-1 receptor agonists should not be used with other GLP-1 RAs or dipeptidyl peptidase-4 inhibitors 2

• Overlooking potential drug interactions:

  • GLP-1 RAs can delay gastric emptying, potentially affecting absorption of other medications 2
  • Document all concurrent medications that may compound gastric emptying effects 2