Adverse Reactions to Methylphenidate ADHD Treatment Aren't Serious

Although children with attention deficit hyperactivity disorder (ADHD) often experience decreased appetite and sleep disturbances during methylphenidate treatment, a study published in the Journal of Research in Pharmacy Practice indicates that those adverse drug reactions (ADRs) are mostly mild and not serious.

From September 2013 to March 2014, researchers observed children and adolescents with ADHD who were being treated with methylphenidate in order to determine the characteristics of common methylphenidate ADRs. The ADRs were assessed for causality and seriousness through relevant World Health Organization definitions, and a questionnaire was used to assess the preventability of ADRs.

A qualified pharmacist recorded all ADRs that occurred after starting methylphenidate treatment, and all 71 patients enrolled in the study experienced at least 1 such ADR. Face-to-face interviews with the patient or his or her parents were conducted at regular follow-up office visits through a checklist of methylphenidate ADRs.

In the study, patient-reported ADRs were classified as either “always,” occurring a daily basis for the recent 1 to 2 week period, or “sometimes,” occurring 2 to 3 times per week during the previous 1 to 2 week period.

The majority of the patients had no underlying diseases (61.9%), although neonatal jaundice (25.4%) and seizure (4.2%) were the most common comorbidities. About half of the ADHD patients were receiving methylphenidate as monotherapy (56.2%).

The investigators detected 38 different types of methylphenidate ADRs, the most frequent of which were anorexia (74.3%), irritability (57.1%), and insomnia (47.2%). However, none of the ADRs were considered to be serious, and all except 1 were deemed as mild.

Although nearly three-quarters of parents observed decreased appetite in their children during methylphenidate treatment, the researchers noted that the ADR is primarily mild, dose-dependent, and may resolve with time. The authors advised parents to administer methylphenidate after a meal, encourage high-calorie foods, and offer an evening or bedtime snack in order to manage this side effect.

“Our data suggested that although methylphenidate-related ADRs were common in children with ADHD, they were mainly mild and nonserious,” the authors concluded, adding that their study was the first to explore the preventability, severity, and seriousness of such ADRs. “…Our preliminary data could be used to establish a database of methylphenidate safety.”