Patterns of Weight Loss Medication Utilization and Outcomes Following Bariatric Surgery

Background Bariatric surgery is the most effective treatment for obesity; however, some patients experience significant weight regain. Weight loss medications (WLM) are being increasingly used in surgery patients with limited evidence. We examine weight loss outcomes in patients using WLM after bariatric surgery. Methods In a retrospective study, 197 bariatric surgery patients who started WLM between 2016 and 2019 at a single center were analyzed. Patients were categorized into 3 groups based on outcomes of the initial surgery: (1) Weight regainers (WR) = achieved goal weight loss after surgery (15% total body weight loss (TBWL) for sleeve gastrectomy (SG) and 25% TBWL for Roux-en-Y gastric bypass (RYGB)) with subsequent regain of > 20% of weight lost; (2) Adequate weight loss (AWL) = achieved goal weight loss without > 20% weight regain; (3) Non-responders (NR) = never achieved goal weight loss. Weight loss and medication use patterns were analyzed. Results Among the three categories, there was no significant difference in duration of medical therapy or %TBWL with medications. RYGB patients lost more weight than SG patients using WLM ( p = 0.03). Of the medications used, patients treated with phentermine + topiramate had the highest likelihood of achieving 5%, 10%, and 15% weight loss. Compared to other 2 groups, AWL group initiated WLM earlier and experienced more weight loss when compared to their pre-operative weight or post-operative nadir. Conclusions RYGB patients respond better to WLM than SG patients. Those who had started WLM before regaining weight (AWL) experienced greater overall weight loss, suggesting that proactive medical therapy at the time of weight plateau can help with greater total weight loss. Phentermine + topiramate is the most effective WLM in post-bariatric surgery patients.