methylphenidate hydrochloride /-fen″idāt/ , a central nervous system stimulant. ▪ INDICATIONS: It is prescribed in the treatment of attention deficit hyperactivity disorder in children and, more recently, in adults and for narcolepsy in adults. ▪ CONTRAINDICATIONS: Glaucoma, severe anxiety, tension, mental depression, or known hypersensitivity to this drug prohibits its use. It is not given to children less than 6 years of age. ▪ ADVERSE EFFECTS: Among the more serious adverse effects are nervousness, insomnia, and anorexia. Hypersensitivity reactions and tachycardia may occur.