Efficacy of Oral Medication in Weight Loss Management: A Systematic Review and Network Meta-Analysis

Purpose: This systematic review was conducted to determine which type of oral medication for obesity provides the best weight loss effect.

Methods: This study adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guideline. For this systematic review, we used 3 databases for journal searches: PubMed, ScienceDirect, and Scopus. This study only included randomized controlled trials or open-label clinical trials. There was no year limit used in the journal search for this systematic review.

Findings: Eighteen randomized controlled trials, with a total population of 12,259 patients, were included. Of 18 studies, 15 were used for network meta-analysis. Based on the results of the network meta-analysis, weight loss was found in phentermine/topiramate (mean difference [MD], -3.28; 95% CI, -4.47 to -2.09), semaglutide (MD, -2.92; 95% CI, -4.38 to -1.46), phentermine (MD, -2.31; 95% CI, -3.82 to -0.81), naltrexone/bupropion (MD, -1.68; 95% CI, -2.87 to -0.49), topiramate (MD, -1.67; 95% CI, -2.86 to -0.48), and orlistat (MD, -1.44; 95% CI, -2.32 to -0.55). There were no significant differences among the groups. However, compared with placebo, all oral obesity therapies provide better benefits in weight loss (MD, -2.12; 95% CI, -2.64 to -1.59; P ≤ 0.00001).

Implications: Oral antiobesity drugs provide better weight loss than placebo. However, some side effects can be incurred by utilizing the drug for weight loss, especially related to the gastrointestinal system. Nonetheless, in clinical settings, consideration should be given to particular patients to reduce risk of side effects.