Find a comprehensive guide to possible side effects including common and rare side effects when taking Concerta (Methylphenidate Extended-Release Tablets) for healthcare professionals and consumers. Methylphenidate ER (Concerta) is an expensive drug used to treat attention-deficit hyperactivity disorder. It is also used to treat narcolepsy. Need help paying for your CONCERTA® (methylphenidate HCI) Extended-release Tablets CII prescription? We want to guide you to programs that may help. Learn about the potential side effects of Concerta (methylphenidate). Includes common and rare side effects information for consumers and healthcare professionals. Many think Concerta (methylphenidate) is safe, or mild, because so many children use it. However, the government classifies the psychoactive drug with cocaine and morphine because it is highly addictive. Is CONCERTA ® Right for Me? Effective Symptom Control. Adults with ADHD may find it difficult to manage such day-to-day responsibilities as getting organized, accomplishing tasks, and keeping appointments. Stimulants Concerta: Frequently Asked ADHD Medication Questions. Concerta is a popular stimulant medication primarily used to treat ADHD in adults and children ages 6 and up. Concerta (methylphenidate) is a central nervous system stimulant. It affects chemicals in the brain and nerves that contribute to hyperactivity and impulse control. Information on the drug methylphenidate (Ritalin, Ritalin SR, Ritalin LA, Concerta, Methylin, Methylin ER, Daytrana, Quillivant XR Metadate CD, Metadate ER) prescribed for the treatment of ADHD and Narcolepsy. Side effects and dosing information is included. Methylphenidate is a central nervous system stimulant. It affects chemicals in the brain and nerves that contribute to hyperactivity and impulse control.