Emergence of tics in children with ADHD: impact of once-daily OROS methylphenidate therapy

While stimulants are the recognized first-line choice of pharmacotherapy for ADHD, reports that they may induce or exacerbate tics have tended to limit their use in ADHD children who have a history of tics or a family history of Tourette's syndrome. This study analyzes the incidence of tics reported across five studies of children with ADHD who received methylphenidate (MPH)-based therapy as part of the clinical development program for once-daily OROS MPH (CONCERTA McNeil Consumer & Specialty Pharmaceuticals, Fort Washington, PA). Data were analyzed from three placebo-controlled, active-controlled studies (studies 1-3) lasting 1-4 weeks, and two open-label studies lasting 2 years (study 4) and 9 months (study 5), respectively. During the course of the studies, parents were asked at the end of each week of treatment (studies 1 and 2), biweekly (study 3), or monthly (for the first year of study 4, then at 3-month intervals thereafter) whether their child had experienced tics. Tics could also be reported as adverse events in the two open-label studies. Pooled data from the three placebo-controlled studies showed that the incidence of tics was not significantly different across all three treatment groups (OROS MPH, 4.0%; MPH tid, 2.3%; placebo, 3.7%, p = 0.5249). During the first year of the 2-year open-label study, the monthly incidence of tics remained constant, at approximately 5%. Analysis of tic episodes per patient in this study found no correlation between an OROS MPH dose and the frequency of tic episodes. The risk of tic episodes was higher in patients with a history of tics than in those with no history of tics (33% versus 7%, p < 0.0001). However, only 2 children with a history of tics (4%) withdrew from therapy because of their tics. These data suggest that MPH-based therapy does not significantly induce or exacerbate tics in children with ADHD.