Safety of Attention-Deficit/Hyperactivity Disorder Medications in Children: An Intensive Pharmacosurveillance Monitoring Study

Abstract

Our intensive pharmacosurveillance monitoring program was performed to increase the number of adverse drug reactions (ADRs) recorded in the Italian spontaneous reporting database, and to systematically collect more thorough data about atomoxetine (ATX) and methylphenidate (MPH) safety in the pediatric setting. From September 2007 to October 2010, 1841 youth were enrolled in the Italian Attention- Deficit/Hyperactivity Disorder Register, but we report here on the 76 children from the five Reference Prescription Centers in Campania, an Italian region where we administered our systematic adverse event checklist. Among our cohort, 68 children received a prescription of ATX and 8 received a prescription of MPH. Most children were male and between 10 and 13 years of age, had a diagnosis of attention-deficit/hyperactivity disorder-combined (ADHD-C) and had learning disability as the main comorbidity. Most ADRs reported to the Italian spontaneous reporting database occurred in patients from Campania. Twenty-five experienced at least 1 ADR for a total of 40 ADRs reported to the Italian drug agency. Most ADRs were common and not serious, and resolved completely. Weight loss was the most frequently reported ADR. Only two ADRs were unexpected and only one was uncommon. Sixteen ADRs resulted in permanent drug withdrawal. Based on the Naranjo algorithm, 25 ADRs were considered "probable" and 15 were considered "possible." Although our data provide reassurance of the safety of ATX and MPH, several unexpected or uncommon ADRs (hepatomegaly, suicidal ideation, weight gain, or drug interactions) were identified by our intensive pharmacosurveillance monitoring program. Our results show that an intensive pharmacosurveillance monitoring program that involves pharmacovigilance centers and clinicians can improve the collection of information on drug safety in children.