Five RCTs met the inclusion criteria (8,315 patients; range 57 to 4,004). Two of the RCTs had follow-up less than one year (eight or 12 weeks), so three RCTs (7,789 patients) were included in the meta-analyses. One RCT scored 5, two scored 4 and two scored 3 on the Jadad scale; all trials scored 3 for level of blindness (all reported being double-blind) and four used an intention-to-treat analysis.
Lorcaserin resulted in a statistically significant additional weight loss of 3.23kg (95% CI 2.70 to 3.75; Ι² 59%) and reduction in BMI of 1.16kg/m² (95% CI 0.98 to 1.34; Ι² 62%) compared to placebo. Lorcaserin significantly decreased average waist circumference by 2.51cm (95% CI -3.04 to -1.99), systolic blood pressure by 0.61mmHg (95% CI -1.16 to -0.07), diastolic blood pressure by 0.49mmHg (95% CI -0.88 to -0.11), total cholesterol (WMD -1.06, 95% CI -1.07 to -0.42), low-density lipoprotein-cholesterol (WMD -1.29, 95% CI -2.32 to -0.25) and triglycerides (-4.70, 95% CI -6.53 to -2.87). There was no significant difference in the change in heart rate or high-density lipoprotein-cholesterol. Headache, nausea and dizziness were statistically significantly associated with lorcaserin. The results of sensitivity analyses were reported.
Two RCTs that compared lorcaserin to placebo had only short-term follow-up; one reported significant reductions in total cholesterol and low-density lipoprotein-cholesterol, and the other reported reductions in total cholesterol, high-density lipoprotein-cholesterol and triglycerides and a significant reduction in weight.