Comparison of the real-world safety of two different long-acting methylphenidate formulations (Medikinet® MR and Concerta®) – a Danish nationwide register-based cohort study

Medikinet MR and Concerta are long-acting methylphenidate formulations used for the treatment of pediatric and adult attention-deficit/hyperactivity disorder (ADHD). The two formulations have shown comparable safety profiles in two head-to-head randomized controlled trials. However, real-world studies comparing the safety profiles of these products are not available. This study aimed to compare the real-world safety of Medikinet MR and Concerta using register data. This population-based cohort study was conducted based on data from Danish registries. The study included patients with continuous long-term (i.e., ≥12 months) exposure to either Medikinet MR or Concerta between 1995 and 2018. Outcomes included several selected adverse events of interest. A sensitivity analysis was performed, excluding patients exposed to Concerta generics. For each outcome, Fisher's exact test was performed to compare the number of cases between the two groups. Odds ratios (ORs) and 95% confidence intervals were estimated using logistic regression models with patients exposed to Concerta as the reference group. The study population included 1249 patients exposed to Medikinet MR and 2455 patients exposed to Concerta®. No cases of cerebral arteritis or priapism were identified in either cohort. ORs for sudden death and anorexia could not be calculated due to the absence of cases in the Medikinet MR cohort. For the remaining outcomes, no statistically significant difference in risk was found between Medikinet MR-exposed and Concerta -exposed patients. The sensitivity analysis produced results consistent with those obtained in the main analysis. The results of this population-based cohort study indicate that Medikinet MR and Concerta have comparable real-world safety profiles.