Off-label use may not be ideal
“Ideally, children with obesity should be entered into a clinical trial rather than placed on an off-label medication,” Vandana Raman, MD, and Carol M. Foster, MD, said in a related commentary. Still, treatment with metformin may be reasonable in certain cases, said Dr. Raman and Dr. Foster of the division of endocrinology in the department of pediatrics at the University of Utah in Salt Lake City. “Metformin is a low-cost option and may provide modest clinical benefit for weight loss with minimal side effects. If lifestyle modification has been pursued but has achieved minimal weight loss, it may be reasonable to try an agent such as metformin as adjunctive therapy,” they said.
Lifestyle modification therapy – including nutritional changes, physical activity, and behavior modification – has been the “mainstay of management” for patients with obesity, and this approach underpins successful weight loss, they said. But durable weight loss with lifestyle modification may be challenging, and pharmacologic treatments “are attractive options before proceeding to bariatric surgery,” they said.
For younger patients, FDA-approved medications for obesity include orlistat and liraglutide for patients aged 12 years and older, and phentermine for patients aged 16 years and older.
“Orlistat has been associated with modest BMI reduction but may cause intolerable gastrointestinal side effects and possible fat-soluble vitamin deficiency,” they said. “Phentermine is approved for short-term therapy only and may increase heart rate and blood pressure and cause irritability and insomnia.”
Liraglutide, which was approved for the treatment of pediatric obesity in December 2020, reduced BMI in a trial that included adolescents with obesity. About 43% of the participants who received liraglutide, compared with 18% who received placebo, had a 5% reduction in BMI. In addition, 26% and 8%, respectively, had a 10% reduction in BMI. The use of liraglutide “is limited by the need for daily subcutaneous injections and high frequency of gastrointestinal side effects and high cost,” however, the commentary authors noted.
In addition, the FDA has approved setmelanotide for children older than 6 years with obesity caused by three rare genetic conditions.
Some small studies have suggested that topiramate may lead to meaningful weight loss in children, but the medication has been associated with cognitive dysfunction, they said.
Considering surgery
“This is an important review of the efficacy of metformin as a tool for weight loss in children with obesity,” said Suzanne C. Boulter, MD, adjunct professor emeritus of pediatrics and community and family medicine at the Geisel School of Medicine at Dartmouth in Hanover, N.H. “Results showed modest decreases in BMI z scores compared to placebo but there were a significant percentage of GI side effects and dropouts from the trials.”
Dr. Suzanne C. Boulter
“Tools other than lifestyle changes are needed to address” pediatric obesity, Dr. Boulter said. “Another tool is gastric bypass which is now a recommended intervention in selected clinical sites for adolescents 14 years of age and older with BMIs greater than 35.”
Dr. Boulter highlighted a recent study in Pediatrics that examined data from more than 200 adolescents who underwent bariatric surgery. The researchers found that outcomes were similar for older and younger patients.
“It would be interesting to pediatricians in practice to see a comparison study between metformin and bariatric surgery long-term results,” Dr. Boulter added.
Dr. Masarwa and coauthors received support from the Quebec Foundation for Health Research and the Canadian Institutes of Health Research Drug Safety and Effectiveness Cross-Disciplinary Training Program. One coauthor also is supported by an award from McGill University.
The authors of the systematic review and the accompanying commentary had no relevant financial disclosures. Dr. Boulter is a member of the editorial advisory board for Pediatric News and had no relevant financial disclosures.