Comparison of the effects of different doses of memantine in combination with methylphenidate in children affected by ADHD

Introduction: Children with Attention-Deficit/Hyperactivity Disorder (ADHD) respond differently to methylphenidate treatment. Memantine has been considered for the treatment of these patients and its prescriptive dose is discussed by researchers. The aim of present study was to investigate the effect of adding different doses of memantine to methyphenidate in the treatment of children with children with ADHD. Material and Methods: In a double blind clinical trial, 72 patients with ADHD were evaluated. Patients randomly divided into two groups. Group one received lower doses of memantine (0.1-0.25 mg/kg) and Methylphenidate; group two received higher doses of memantine(0.25-0.5 mg/kg) and Methylphenidate for six weeks. 39 patients who continued the study until the end, at the week zero, second, fourth and sixth, their demographic and clinical information were assessed by demographic questionnaire and Conners Parent Questionnaire. SPSS version 20 was used for statistical analysis. Results: The mean age of patients was 9.51 +/- 2.29 years and their weight was 27.38 +/- 8.31 kg and 12.8% of them were female. A total of 16 patients in group one and 23 patients in group two completed the study. Two patients of group one and three patients of group two were excluded due to drug complications, which, all of whom were male. The mean score of the Conners at the baseline of study was 23.84 +/- 2.44 and in the sixth week, it was 12.58 +/- 2.89. Moreover, no significant difference was found at any time range: baseline (p=0.275), second week (p=0.921), fourth week (p=0.7) and sixth week (p=0.966). The Conners score in both groups was significantly reduced over a 6-week period of treatment. also, the mean heart rate of the patients in group two in the 4th week (p=0.01) and the 6th week (p=0.02) was significantly lower than group one while the systolic blood pressure in group two after six weeks of treatment was significantly increased (p=0.01). Conclusion: Memantine was effective in the treatment of patients with hyperactivity disorder, and constantly reduced patients' Conners score over a 6-week period. However, no significant difference was observed between patients receiving higher dose of memantine and patients given lower dose of memantine. Therefore, given the increased risk of the related side effects, it is advisable to prescribe a lower dose of memantine along with methylphenidate.