Dexmethylphenidate hydrochloride. Molecular model of the drug dexmethylphenidate hydrochloride (C14.H19.N.O2?H.Cl). This drug, sold under the brand name Focalin, is a central nervous system (CNS) stimulant of the phenethylamine and piperidine classes. It is used in the treatment of attention deficit hyperactivity disorder (ADHD) and narcolepsy. Atoms are represented as spheres and are colour-coded: carbon (grey), hydrogen (white), nitrogen (blue), oxygen (red) and chlorine (green).