What Glucagon-like peptide-1 (GLP-1) receptor agonist can be prescribed to a 13-year-old obese patient?

GLP-1 Receptor Agonist for a 13-Year-Old with Obesity

Liraglutide 3.0 mg (Saxenda) is the only GLP-1 receptor agonist approved for obesity treatment in adolescents aged 12 years and older, making it the appropriate choice for this 13-year-old patient. 1, 2

FDA-Approved Option

Liraglutide 3.0 mg is FDA-approved for chronic weight management in adolescents aged ≥12 years with obesity (BMI ≥95th percentile for age and sex) or overweight (BMI ≥85th percentile) with weight-related comorbidities. 1, 2 This approval was granted in 2020 specifically for the pediatric population, making it the first and only GLP-1 receptor agonist with this indication in children 3.

Dosing Protocol for Adolescents

• Start at 0.6 mg subcutaneously once daily for at least one week 2
• Increase to 1.2 mg daily if additional glycemic control or weight loss is needed 2
• May escalate to 1.8 mg daily after at least one week at the 1.2 mg dose if further benefit is required 2
• The maximum approved dose for adolescents is 1.8 mg daily, not the 3.0 mg dose used in adults for obesity 2

Clinical Evidence in Adolescents

Liraglutide demonstrates significant efficacy in adolescent obesity, with a mean BMI reduction of 0.22 standard deviations compared to placebo over 56 weeks. 4 In the SCALE Kids trial involving children aged 6 to <12 years, liraglutide achieved a -5.8% change in BMI versus +1.6% with placebo (difference of -7.4 percentage points, p<0.001) 5. While this specific trial was in younger children, it demonstrates the medication's efficacy across pediatric age groups.

Among adolescents aged 12-17 years with obesity, 46% achieved ≥5% BMI reduction with liraglutide versus 9% with placebo. 5 The medication also produces meaningful improvements in cardiometabolic parameters beyond weight loss 3.

Safety Profile and Monitoring

Gastrointestinal adverse effects are the most common side effects, occurring in approximately 80% of pediatric patients, compared to 54% with placebo. 5 These include nausea, vomiting, diarrhea, and constipation, which are typically mild-to-moderate and decrease over time 3, 6.

Critical Contraindications

• Absolute contraindication: Personal or family history of medullary thyroid carcinoma (MTC) or Multiple Endocrine Neoplasia syndrome type 2 (MEN2) 2
• Serious hypersensitivity reaction to liraglutide or any excipients 2

Important Warnings

• Monitor for pancreatitis: Discontinue immediately if suspected 2
• Risk of acute kidney injury, particularly with dehydration from gastrointestinal side effects 2
• Acute gallbladder disease: Obtain gallbladder studies if cholelithiasis or cholecystitis suspected 2
• Hypoglycemia risk is higher in pediatric patients regardless of concomitant medications 1

Alternative Considerations

Liraglutide for type 2 diabetes (Victoza) can be used in children ≥10 years old with type 2 diabetes, but this 13-year-old has obesity without diabetes, making the obesity-specific formulation (Saxenda) more appropriate. 1

Semaglutide has shown superior weight loss in adolescents (mean difference of -17.70 kg compared to placebo) but is not yet FDA-approved for pediatric obesity. 6 Clinical trials are ongoing, but off-label use is not recommended outside research settings 1.

Exenatide has been studied in small pediatric trials but lacks FDA approval for this indication and shows less pronounced effects than liraglutide. 6

Essential Adjunctive Therapy

Liraglutide must be combined with lifestyle interventions including reduced-calorie diet, minimum 150 minutes/week of physical activity, and behavioral counseling. 1, 2 Medication alone without lifestyle modification produces suboptimal results 1.

Treatment Evaluation Timeline

Assess treatment response at 12-16 weeks on the maximum tolerated dose. 1 If BMI reduction is <4% after 12 weeks at maximum dose, consider discontinuation and alternative approaches 1. Early responders (≥5% BMI reduction after 3 months) should continue long-term therapy 1.

Common Pitfalls to Avoid

• Do not use the adult 3.0 mg dose in adolescents—the maximum approved pediatric dose is 1.8 mg daily 2
• Do not prescribe semaglutide or tirzepatide off-label for pediatric obesity outside clinical trials 1
• Do not initiate without screening for MTC/MEN2 family history 2
• Do not discontinue abruptly if gastrointestinal side effects occur—slow titration minimizes these effects 3
• Never share liraglutide pens between patients, even with needle changes 2