[Studies on the adverse effects of fluvoxamine treatment in children with autistic disorder: correlation with genetic polymorphism in serotonin related genes]

Abstract

Selective serotonin re-uptake inhibitors (SSRIs) have recently been applied to the children with autistic disorder. To create better treatment, we studied here clinical adverse effects of fluvoxamine and correlated them with genetic polymorphism of two genes, the promoter region of serotonin transporter gene (5-HTTLPR) and serotonin 2A receptor gene (5-HT2AR). Twenty-eight subjects, consisting of 23 boys and 5 girls, aged from 3 to 18 years old diagnosed as having autistic disorder were analyzed during fluvoxamine administration. The dosages and duration of fluvoxamine treatment are 1.5 to 3 mg/kg/day and 2 weeks to 17 months (mean 7.9 months), respectively. There were several clinical adverse effects such as sleep disturbance in 9 cases, climb up to high places in 8, gastrointestinal symptoms in 6, hyperactivities in 5, excitement in 4, general fatigability in 2 and urticaria in 1. Medication was discontinued in 2 patients with fatigability and 1 with sleep disturbance, diarrhea and poor appetite. There was no significant correlation between genetic polymorphism in 5-HTTLPR and the occurrence of clinical adverse effects of fluvoxamine. However hyperactivity was significantly more frequent in the subjects with 102T/102T polymorphism of 5-HT2AR, and patients with sleep disturbance were significantly less frequent in the subjects with 102C/102C polymorphism. We conclude that the clinical adverse effects such as climb up to high places and hyperactivity during fluvoxamine treatment may be relatively specific in children, and that genetic polymorphism of 5-HT2AR may be related to the appearance of clinical adverse effects.