Belviq (Lorcaserin): A 5-HT2C receptor agonist indicated to treat certain overweight or obese adults

Obesity increases patients' risk of heart disease, stroke, type 2 diabetes, and certain types of cancer, and costs the healthcare system about $147 billion per year. On June 27, 2012, FDA approved lorcaserin as an adjunct to a reduced-calorie diet and increased physical activity for chronic weight management in adults with an initial body mass index ≥30 kg/m² (obese) or ≥27 kg/m² (overweight) in the presence of at least 1 weight-related comorbid condition (eg, hypertension, dyslipidemia, type 2 diabetes).

Efficacy. Lorcaserin is believed to decrease food consumption and promote satiety by selectively activating 5-HT_2C receptors located in the hypothalamus. Lorcaserin 10 mg twice daily was evaluated in 3 randomized, double-blind, placebo-controlled trials with durations of at least 52 weeks (2 in adults without type 2 diabetes and 1 study in adults with type 2 diabetes). Statistically significantly greater weight loss was achieved with lorcaserin in both non-diabetics compared to placebo at week 52 (placebo-adjusted weight loss with lorcaserin was 3.3 kg, 95% CI, -3.6, -3.0) and in type 2 diabetics (placebo-adjusted weight loss with lorcaserin was 3.1 kg, 95% CI, -3.9, -2.2). Moreover, about 47% of patients without type 2 diabetes lost ≥5% of their body weight compared with 23% of patients treated with placebo. In patients with type 2 diabetes, 38% of patients treated with lorcaserin lost ≥5% of their body weight versus 16% receiving placebo.

Safety. In clinical trials of lorcaserin lasting at least 1 year, the most common adverse reactions occurring in >5% of non-diabetic patients were headache, dizziness, fatigue, nausea, dry mouth, and constipation. In diabetic patients, the most common adverse reactions were hypoglycemia, headache, back pain, cough, and fatigue. Other safety concerns included: serotonin syndrome or neuroleptic malignant syndrome (NMS)-like reactions, hypoglycemia (due to weight loss in type 2 diabetics), valvular heart disease, cognitive impairment, psychiatric disorders (ie, euphoria, hallucination, and dissociation), heart rate decreases (of ~1.2 to 2.0 beats per minute), decreases in red and white blood cell counts, and priapism. The drug's manufacturer will be required to conduct 6 postmarketing studies, including a long-term cardiovascular outcomes trial to assess the effect of lorcaserin on the risk for major adverse cardiac events such as heart attack and stroke.