P0212 - Pharmacotherapy for Weight Loss in Children, Adolescents, and Young Adults: An Evaluation of Current On- and Off-Label Usage

Lifestyle modifications focused on diet, physical activity, and behavior have only a modest impact on weight reduction in children, adolescents, and young adults (YA) with overweight and obesity. Several anti-obesity medications (AOMs) have been approved by the Food and Drug Administration (FDA) for use among adult patients with a body mass index (BMI) ≥27 kg/m2 and at least one obesity-related illness. However, only two FDA-approved AOMs are available for use in children and adolescents, which leads to the frequent off-label use of adult AOMs among this population. We sought to investigate current prescribing patterns of on- and off-label AOMs across a spectrum of age ranges from school age through to young adulthood and assess the effectiveness of these medications in achieving weight loss.

Using a centralized clinical data registry containing the health data of approximately 6.5 million patients, individuals aged 5 to 25 years old with overweight and obesity who were taking one of eight commonly prescribed AOMs from 2009-2018 were extracted. A total of 1,720 patients were identified, representing 2,210 medication prescribing instances. The cohort was further stratified as children (5-12 years old), adolescents (13-18 years old), and YA (19-25 years old). The mean BMI at the time of medication initiation for each subgroup was 34.0 kg/m2, 39.1 kg/m2, and 39.6 kg/m2, respectively, which corresponded to a BMI z-score (BMIz) of 2.4 and 2.3 for children and adolescents, respectively. Metformin was the most commonly prescribed medication across all ages, including off-label use for weight-loss among children and adolescents. The most commonly off-label prescribed AOM among YA was topiramate. Multivariable analyses demonstrated phentermine was the most effective AOM, with a 1.54 % total body weight among YA (p=0.05) and a 0.12 decrease in BMIz among adolescents (p=0.003) greater final weight loss when compared to the respective overall frequency-weighted means. Our study demonstrates a statistically significant weight loss among adolescents and young adults on select pharmacotherapy. The small magnitude of this effect should be interpreted carefully, as it is likely an underestimate in the absence of a true control group.

Our study demonstrates that AOMs may play a role in weight management for adolescents and young adults with obesity and should be considered as an important component of a multimodal approach to managing this chronic condition. Their use may become particularly important as patients who undergo lifestyle modification or metabolics and bariatric surgery continue to face challenges with attaining and maintaining appropriate, durable weight loss. Prospective studies should be conducted to better understand the impact of these medications in the pediatric population.