The GABAergic control of the hungry. Topiramate in the treatment of obesity without binge eating disorders (BED). Preliminary data

Abstract

Background: Topiramate is an antiepileptic drug, with anoressant effect, known to positively modulate GABA receptors. There are some published data concerning the use of topiramate in mood disorders (especially BED), while there are not know data on its use in obese patients without BED. Aim: This is a preliminary study to explain the effectiveness and tolerability of topiramate in non-BED obese patients. Method: We described the effects of topiramate (150mg daily), without a low-calorie diet, on weight and metabolic control in 6 subjects (1 male and 5 females, aged 38 to 68 years) treated for consecutively 6 months (between November 2002 to April 2003). The inclusion criteria is BMI above 30kg/m2, abdominal obesity, hypertriglyceridemia, high fasting glucose and low HDL-cholesterol levels. The exclusion criteria included: BED and others mood disorders, epilepsy, pregnancy, lactation, any kind of psychotherapy and psychiatric drug or antiobesity agents within 3 months of entry to the study. The dosage of topiramate was gradually increased in increments of 25mg every week from 25mg twice daily in the first two weeks to the target dosage of 75mg twice daily at the end of second month of treatment. This dosage was maintained until the end of this study. Results: Topiramate induced significant weight loss. The mean weight loss was 6,8kg and was present significativelly descrease of visceral fat (mean 2,1cm in waist circumference). Subjects who lost 10% of the weight showed significant decreases in fasting plasma glucose (mean 21,6mg/dl) and in plasma triglycerides (mean 33,4mg/dl). In general topiramate was well tolerated. The most adverse events reported were transient (paresthesias 1 case, fatigue 1 case, somnolence 1 case). In 3 cases there were not adverse effects. Discussion: Treatment with topiramate decreased BMI and visceral fat, decreased triglycerides and fasting plasma glucose levels, but had not improved HDL-cholesterol blood levels. Topiramate at 150mg daily had not increased diastolic blood pression and pulse rate and may be a suitable option to sibutramine in obese patients with high blood pressure. In conclusion our preliminary data suggests that topiramate may be an effective and well-tolerated agent for the control of the hungry in the treatment of obese patients, but this is a study with very few patients. Other controlled study need to be performed to evaluate the use of topiramate in obese population and, in particular, the benefits of topiramate therapy in patients with metabolic syndrome without BED.