Safety and efficacy of therapy with botulinum toxin in obesity: a pilot study

Background: Botulin toxin (BTX) has been proposed as a potential obesity treatment. Methods: In a pilot study, the short-term efficacy and safety of BTX was assessed in eight subjects (four men, four women; median age, 46 years; range, 35-57 years) with severe obesity (median body mass index [BMI], 47.1 kg/m(2); range 38.2-56.7 kg/m(2)) and multiple dietary treatment failures. In a single endoscopic session, 500 UI of BTX-A was injected in the gastric antral region. Results: No clinically significant side effects were observed. In all patients, despite their not being on a specific diet, a reduction of body weight was observed at 1 month (median baseline weight, 124.4 kg vs 121.8 kg at 1 month; P < 0.05). Two treatment-unrelated dropouts were observed. At 4 months, three of the six patients had a further weight loss. The treatment effect was apparently independent of changes in hunger or satiety, or of changes in fasting and postprandial plasma ghrelin and serum leptin, thus suggesting a different pharmacological mechanism. Conclusions: BTX-A treatment appears to be safe and well tolerated by obese patients, while its short-term efficacy varied widely.