IRCT201204037202N5 IRCT 2012-06-20 Tehran University of Medical Sciences Comparing efficacy and side effects of Memantine and Risperidone in treating autistic patients Comparing efficacy and side effects of Memantine and Risperidone in treating autistic patients 2012-06-21 anticipated 30 Complete https://irct.ir/trial/7627 interventional Randomization: Randomized, Blinding: Not blinded, Placebo: Not used, Assignment: Parallel, Purpose: Treatment. 3 Autism. Intervention 1: Risperidone with gradual increasing in dose will be prescribed as bellow: 0.02mg/kg/day at begining, 0.04 mg/kg/day at second week and ultimately will be increased to 0.06 mg/kg/day at third week. Calculated dose based on body weight will be rounded to the nearest dose that according to the available dosage form of risperidone can easily be prescribed. Maximum daily dose of risperidone will be 3 mg. Intervention 2: Memantine with gradual increasing in dose will be prescribed as bellow: 0.2mg/kg/day at begining, 0.3mg/kg/day at second week and ultimately will be rised to 0.4mg/kg/day at third week. Calculated dose based on body weight will be rounded to the nearest dose that according to the available dosage form of memantine can easily be prescribed. Maximum daily dose of memantine will be 20 mg.