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

Background: 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.

Objective: This study aimed to compare the real-world safety of Medikinet^® MR and Concerta^® using register data.

Method: 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.

Results: 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.

Conclusions: The results of this population-based cohort study indicate that Medikinet^® MR and Concerta^® have comparable real-world safety profiles.