20 to 30% of children with attention deficit/hyperactivity disorder(ADHD) do not respond or could not tolerate methylphenidate treatment. Drug transporters such as multidrug resistant proteins(MDR) plays important role in the clearance of psychotropic drugs and their metabolites from brain tissue. It suggested that methylphenidate was a P-glycoprotein(encoded by MDR1 gene)substrate and showed inhibitory effects on the P-glycoprotein efflux function. Single nucleotide polymorphisms(SNP)in the MDR1 gene were analyzed in children and adolescents with OROS-methylphenidate treatment. The hypothesis is that MDR1(ABCB1) polymorphisms are associated with the side effects of OROS-methylphenidate.
The purpose of this study is to examine whether genetic polymorphisms in drug transporters were associated with the side effects of OROS-methylphenidate medication in attention deficit/hyperactivity disorder(ADHD).