Clinical Question: Is orlistat (Xenical) effective for weight management in obese adolescents?

Setting: Outpatient (any)

Study Design: Randomized controlled trial (double-blinded)

Allocation: Concealed

Synopsis: Investigators identified 539 adolescents, 12 to 16 years of age, who met the criteria for obesity (a body mass index [BMI] of more than two units above the 95th percentile for age and sex). Participants were assigned randomly in a double-blind fashion to receive 120 mg of orlistat or placebo three times daily. All patients also received general recommendations for diet, exercise, and behavior modification. Persons blinded to treatment group assignment assessed outcomes. Follow-up for one year occurred for 98 percent of patients. Approximately two thirds of adolescents in each group completed the study.

The investigators performed a modified intention-to-treat analysis that included only patients with a baseline measurement and at least one measurement of effectiveness after baseline. At one year of follow-up, 26.5 percent of adolescents in the treatment group versus 15.7 percent in the placebo group had a 5 percent decrease in BMI, and 13.3 percent in the treatment group versus 4.5 percent in the placebo group had a 10 percent decrease in BMI (number needed to treat = 9; 95% confidence interval, 6 to 31 for both). Weight increased an average of 1.2 pounds with orlistat and 6.9 pounds with placebo (total cost per pound not gained = $374). Overall, BMI decreased by 0.55 in the orlistat group and increased by 0.31 in the placebo group (P = .001). Twelve patients (3.4 percent) taking orlistat and three patients (1.6 percent) taking placebo discontinued treatment because of adverse events, most often problems in the gastrointestinal tract. No major safety issues were reported.

Bottom Line: Orlistat, in combination with diet, exercise, and behavior modification, improves weight management in obese adolescents. No major safety issues were identified after one year, but further follow-up for sustained weight management and safety is important. (Level of Evidence: 1b)