Lorcaserin hydrochloride (Belviq) is a serotonin 2C receptor agonist that causes weight loss by causing appetite suppression.It appears to have fewer adverse effects than orlistat,although long-term safety data are limited. The recommended dosage is 10mg twice daily. Lorcaserin should be discontinued if patients do not lose 5% of their body weight in 12 weeks. The efficacy of lorcaserin appears similar to that of orlistat (mean difference in weight loss between active and placebo-treated groups approximately 3-4 kg).Common side effects include nausea, headache,dizziness, nasopharyngitis, and fatigue. Lorcaserin may increasethe risk of symptomatic hypoglycemia in patients with type 2 diabetes on oral agents, necessitating a reduction in the dose of diabetes medications. Lorcaserin should not be used in individuals with creatinine clearance <30 mL/minute. It is contraindicated during pregnancy. In addition, lorcaserin should not be used with other serotonergic drugs (e.g., selective serotonin reuptake inhibitors,selective serotonin-norepinephrine reuptake inhibitors, bupropion[Wellbutrin], tricyclic antidepressants,and monamine oxidase inhibitors)because of the theoretical potential for serotonin syndrome.
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