Retalin & liver enymesLibrary > Literature & Language > Dictionary ( rĭt ' l-ĭn ) A trademark used for methylphenidate. . Methylphenidate (MPH; Ritalin, Concerta, Metadate, or Methylin) is a psychostimulant drug approved for treatment of attention-deficit hyperactivity disorder, postural . This document may contain dated information. Accurate, FDA approved Ritalin information for healthcare professionals and patients - brought to you by Drugs. , Ritalin and Concerta—... more