Positive Effect of Baclofen on Body Weight Reduction in Obese Subjects: A Pilot Study

Background and objective We previously reported that baclofen, a GABA(B) agonist, reduces body weight in obese mice. In this clinical study, we examined the possibility that baclofen might serve as an effective therapeutic agent for obesity in humans. Methods Seven women and three men ranging from 25-51 years of age and 31.3-41.0 kg/m(2) body mass index were included in the study. Baclofen, which was started at a dose of 15 mg/day and increased to 30 mg/day in 10 days, was administered for 12 weeks. Results Administration of baclofen for 12 weeks significantly decreased both body weight (baseline: 93.30 +/- 9.80 kg, 12 weeks: 91.70 +/- 10.30 kg) and waist circumference (baseline: 107.9 +/- 9.0 cm, 12 weeks: 105.6 +/- 10.0 cm). Serum leptin levels, which possibly reflect the amount of adipose stores, were also decreased significantly by the treatment. On the other hand, there were no significant changes in the blood pressure or metabolism of glucose and lipid. No adverse effects were observed. Conclusion Although the anti-obesity effects of baclofen in the present study were mild, this pilot study suggests the possibility that baclofen might serve as a new anti-obesity drug in humans.