The effectiveness and safety of pharmaceuticals to manage excess weight post-bariatric surgery: a systematic literature review

Objective: To systematically review the literature on weight management pharmaceutical use in patients who have had bariatric surgery.

Methods: Google Scholar, Pubmed, Cochrane, Embase, Web of Science, and Clinical Trials were searched from inception to December 31st, 2018 inclusive.

Results: Thirteen studies met inclusion and reported decreases in weight with the use of weight management medications in post-bariatric surgical patients. Five studies examined weight loss outcomes by the type of bariatric surgery procedure, and four of these studies observed less weight loss in patients who had undergone gastric sleeve compared to those who had roux-en-y bypass (n = 3 papers) and adjustable gastric banding (n = 1 paper) with medication use. Four studies compared the effectiveness of medications for weight management and observed slightly greater weight loss with the use of topiramate and phentermine as a monotherapy compared to other weight loss medications. Using a sub-sample of participants, authors observed less weight loss on metformin but not phentermine or topiramate for younger adults. Another post-hoc analysis in the same sample observed greater weight loss for older adults with liraglutide 1.8 mg. Side effects were reported in seven studies and were overall consistent with those previously reported in non-surgical populations.

Conclusion: Results of this systematic review suggest pharmacotherapy may be an effective tool as an adjunct to diet and physical activity to support weight loss in post-bariatric surgery patients. However, due to most studies lacking a control or placebo group, more rigorous research is required to determine the efficacy of this intervention.