Rising childhood obesity in Korea’s limited environment

Growing number of pediatric patients are recommended pharmacotherapy

Options limited other than Saxenda… need for new alternatives

The need for active management of childhood and adolescent obesity is becoming increasingly emphasized, along with growing interest in the appropriate use of pharmacotherapy.

 

According to the ‘2020 Clinical Practice Guidelines of the Korean Society for the Study of Obesity,’ childhood obesity treatment in Korea primarily focuses on lifestyle modification—including diet, exercise, and behavioral therapy—to maintain appropriate weight.

 

However, when weight continues to increase and comorbidities remain uncontrolled, pharmacological and surgical therapies are recommended along with lifestyle modification.

 

Currently, pharmacological treatment for obese adolescents aged 12 or older is applied very selectively, taking into account both obesity status and growth stage.

 

Medications are recommended in cases such as ▲ adolescents with severe obesity accompanied by complications, ▲ those with a family history of cardiometabolic diseases such as type 2 diabetes, or ▲ those whose weight or complications cannot be controlled despite intensive diet and behavioral therapy.

 

Recommended drugs include GLP-1 receptor agonists such as Saxenda (liraglutide) and Wegovy (semaglutide), the fat absorption inhibitor Xenical (orlistat), and the appetite suppressant combination Qsymia (phentermine/topiramate).

 

◆Obesity patients in need of pharmacotherapy increase among children and adolescents Following the outbreak of COVID-19 in 2020, school attendance and outdoor activities were restricted, leading to decreased physical activity compared to pre-pandemic levels and accelerating the spread of obesity among adolescents.

 

Like adult obesity, childhood obesity is associated with a range of comorbidities, including hypertension, dyslipidemia, type 2 diabetes, non-alcoholic fatty liver disease, obstructive sleep apnea, polycystic ovary syndrome, and mental health disorders such as depression.

 

In children with severe obesity, even more serious cardiometabolic diseases than myocardial infarction or arteriosclerosis have been reported.

 

As a general principle, obesity treatment aims for about 10% weight reduction and maintenance.

 

However, due to the rebound yo-yo effect, one-third to two-thirds of the lost weight is typically regained within one year, and over 95% is regained within 5 years.

 

Therefore, if non-pharmacological interventions such as diet and exercise fail to achieve more than 5% weight reduction after 3–6 months, active pharmacotherapy should be considered.

 

If no meaningful weight loss of at least 5% occurs within 3 months of medication use, a new treatment strategy should be planned.

 

Ultimately, lifestyle modification remains the first-line treatment for childhood obesity.

 

However, for patients who fail to achieve weight loss through this approach, pharmacotherapy may be the best option before considering bariatric surgery.

 

Candidates for obesity pharmacotherapy include those with a BMI above the 95th percentile and weight-related comorbidities, or those with a BMI at least 120% of the 95th percentile, regardless of comorbidity status, who do not respond adequately to lifestyle modification.

 

Specifically, the proportion of obese children and adolescents in Korea requiring pharmacological treatment is currently estimated at 2–3%, and is expected to gradually reach below 5% due to dietary and lifestyle changes.

 

◆Limited pharmacotherapy options and considerations regarding Qsymia The problem is that, unlike abroad, the range of obesity treatments available in Korea is highly limited.

 

Officially, the only drugs approved for use in children and adolescents aged 12 and above are Xenical and Saxenda.

 

Xenical reduces fat absorption in the body.

 

Despite the convenience of being an oral medication, it is used only sparingly due to common side effects such as diarrhea, abdominal pain, and increased intestinal gas.

 

In addition, because it reduces absorption of fat-soluble vitamins, patients must take a daily multivitamin containing these nutrients.

 

The American Gastroenterological Association (AGA) even recommended against using Xenical in its 2022 clinical practice guidelines on pharmacological interventions for adult obesity, citing these adverse effects.

 

Qsymia can be prescribed to children and adolescents in the U.S., but it is not approved in Korea because one of its components, phentermine, is contraindicated for use in patients under 16.

 

However, Qsymia—a combination that contains topiramate—enhances anti-obesity effects while lowering the dosage of each component compared to monotherapy, thereby reducing side effects.

 

It also has the advantage of requiring only once-daily administration, regardless of meals.

 

Concerns about pediatric prescription mainly stem from safety, but accumulating research data continues to address this issue.

 

Clinical pharmacology trials comparing phentermine and topiramate in adults versus adolescents have shown no significant differences in efficacy or safety between the two groups.

 

The studies found that both agents exhibited similar pharmacokinetic characteristics in adolescents and adults.

 

The type, frequency, and severity of adverse drug reactions, as well as discontinuation rates due to adverse events, were also comparable, indicating no major differences in safety or tolerability between the two groups.

 

Professor Seung-Hwan Lee of Seoul National University Hospital’s Department of Clinical Pharmacology stated, “The dose–pharmacokinetic–pharmacodynamic–clinical response relationships for phentermine and topiramate are similar in adolescents and adults.

 

Therefore, the same dosage and regimen can be applied to adolescents as in adults.

 

The adverse reactions are generally not severe and can be managed through dose reduction or discontinuation.”