RESUMEN
Methylphenidate (MPH) is a central nervous stimulant, which is mainly used in attention deficit hyperactivity disorder (ADHD) and narcolepsy. In recent years, rising MPH prescription volumes have drawn attention to possible misuse. We analyzed data on suspected MPH abuse, dependence or withdrawal reported to the EudraVigilance database (1996-2019), comparing case characteristics (e.g. age, indications and outcome). In 1531 cases from 35 countries (median: 29 years, 57.6% male), 42.3% had been diagnosed with ADHD and 8.0% with narcolepsy. Narcolepsy cases were older than ADHD cases (mean age: 47 vs. 22 years), and used co-medications more frequently (79.4 vs. 47.8%). Intravenous MPH administration was most common among individuals not diagnosed with ADHD or narcolepsy. A history of abuse, dependence or withdrawal of any substance was more often documented in fatal than in nonfatal cases (49.0 vs. 22.5%), whereas differences regarding the route of administration were less pronounced. Minors, who presumably received MPH for ADHD treatment, presented less frequently with serious outcomes than older cases or those without an approved indication. Prescribers should exercise caution in adult MPH users and should make a thorough co-medication assessment. Finally, more research on substance abuse in narcolepsy patients is required, which should include comorbidities and co-medication.