The study objective was to examine the association between phentermine/topiramate therapy and weight loss and adverse events in adults with overweight or obesity by meta-analysis and systematic review. Methods: Medical Subject Headings and free-text terms were selected to search for eligible trials in PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), and Embase up to April 18, 2020. The quality of randomized controlled trials was evaluated by the Cochrane riskof-bias tool. Meta-analysis was performed using random-effect models. Results: Phentermine/topiramate therapy resulted in an average weight loss of 7.73 kg (95% CI: 6.60-8.85) in general compared with placebo. The weight loss was related to the dose of phentermine/topiramate. Compared with placebo, the average weight loss was 3.55 kg (95% CI:

Objective: To examine the association between phentermine/topiramate therapy and weight loss and adverse events in adults with overweight problems or obesity by meta-analysis and systematic review. Methods: Medical Subject Headings (MeSH) and free-text terms related to phentermine/topiramate were selected to search for eligible trials in PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), and EMBASE up to April 18, 2020. The quality of randomized controlled trials was evaluated by Cochrane risk-of-bias tool. Meta-analysis was performed using random-effect models. Our systematic review protocol, registered on PROSPERO (registration number CRD42020188324). Results: Phentermine/topiramate therapy resulted in a weight loss of 7.73 kg (95% confidence interval [CI]: 6.60, 8.85) compared to placebo. For phentermine/topiramate subjects in different weight loss subgroups, the weight loss of subjects with ≥5%, ≥10%, and ≥15% baseline weight loss were 3.18 (95% CI: 2.75, 3.67), 5.32 (95% CI: 4.53, 6.25), and 5.65 (95% CI: 3.55, 9.01), respectively. Phentermine/topiramate reduced waist circumference, blood pressure, blood sugar levels, and lipid levels. The adverse effects associated with the treatment mainly included Dysgeusia, Paresthesia, Dry mouth. Conclusions: Phentermine/topiramate reduced body weight and was well tolerated. However, it increased the risk of nervous system-related adverse events to a certain extent, but the symptoms are not serious. Long-term clinical and pharmacological studies are needed to understand the long-term efficacy and safety of phentermine/topiramate.