Letter to the editors Dear Editor, We would like to communicate our experience in patients with eating disorders (ED) treated with Zonisamide, a novel antiepileptic drug of the methane-sulfonamide group. This drug is rapidly absorbed in the gastrointestinal tract and it binds proteins moderately. Zonisamide is thought to act over voltage sensitive sodium channels and on T-type calcium channels. Moreover, Zonisamide alters the metabolism of glutamate, GABA, dopamine, serotonin, acetylcholine and

more »

... carbonic anhydrase. The use of anticonvulsants in patients with ED is a common practice, due to their efficacy on weight and impulsive behaviour. 1,2 The way they work is unknown: probably they act directly via general effect on pathological impulsivity thanks to their action on neurotransmitter systems. For this reason we think that Zonisamide, due to its properties, may be effective not only on binging behaviour but also in reducing self-injury in patients with Bulimia Nervosa (BN) and Binge Eating Disorder. 3 Zonisamide was added to other medications up to the maximum dose of 300 mg and a longitudinal analysis was performed at 3 months and after a year. The 80% of the patients was under treatment with fluoxetine and there was not modification of the pharmacological treatment during the follow-up. The sample consisted of seventeen females patients: see description in Table 1 . Primary outcome measure was binging frequency. Secondary outcomes were Body Mass Index (BMI), Clinical Global Impressions-Severity of Illness Scale (CGI-SI) and self-injury. Ten of the seventeen patients concluded the 12 month follow-up; the other seven patients discontinued for the following reasons: increase of ocular pressure (n = 1), increase of serum creatinine levels (n = 1); paranoid symptoms (n = 1) and withdrawal of the follow-up (n = 4). Due to the little sample size only BMI and CGI-SI were analysed at endpoint visit. The statistical analysis evaluated treatment-by-time interaction effect on BMI, binging behaviour, self-harming and the CGI-SI. A 5.72% reduction of BMI (p = 0.02), a decrease in binges (p = 0.01) and self-harming episodes (p = 0.03) and a significant improvement in CGI-SI (p < 0.00001) were observed after 12 weeks of treatment. Improvement in CGI-SI was prolonged a year after (p < 0.00001), not the improvement of BMI (0.19). According to our review this is the first study that evaluates the efficacy of Zonisamide 1516-4446 -