ADHD is a common neurodevelopmental disorder which is being increasingly recognized, diagnosed and treated, and data from the UK General Practice Research Database demonstrated that the

prevalence of prescriptions for methylphenidate, atomoxetine and dexamfetamine in a sample of 1636 patients increased 6.23 fold between 1999 and 2006 [McCarthy et al. 2009] There are seven currently licensed Inhibitors,research,lifescience,medical and available medications in the UK to treat ADHD: atomoxetine (Strattera®, Eli Lilly & Company Ltd, Basingstoke, UK), dexamfetamine, two short-acting preparations of methylphenidate (Ritalin®, Novartis Pharmaceuticals Ltd, Camberley, UK, Medikinet®, Flynn Pharma Ltd, Dublin, Ireland) and three long-acting preparations of methylphenidate (Concerta XL®, Janssen-Cilag Ltd, High Wycombe, UK, Equasym XL®, Shire Pharmaceuticals Ltd, Basingstoke, UK and Medikinet XL®, Flynn Pharma Ltd, Inhibitors,research,lifescience,medical Dublin, Ireland). Atomoxetine and methylphenidate are the commonest of these prescribed medications in ADHD, with clinical trials demonstrating differential response rates. Newcorn and colleagues, for example, showed that in 44% of patients their ADHD responded to either medication,

whereas in 43% their Inhibitors,research,lifescience,medical condition responded to atomoxetine having failed to respond to methylphenidate, and in 42% it responded to methylphenidate having failed to respond to atomoxetine [Newcorn et al. 2009]. In a noninferiority meta-analysis of comparative clinical trials of at least 6 weeks’ duration, atomoxetine and methylphenidate were both associated with similar responder rates (>40% reduction in ADHD Rating Scale) of 53.6% and 54.4%, respectively, with atomoxetine demonstrating noninferiority

to methylphenidate [absolute difference −0.9%, 95% confidence interval (CI) −9.2% –7.5%] [Hazell Inhibitors,research,lifescience,medical et al. 2010]. A recent systematic review of atomoxetine data between 2009 and 2011 conducted by two of the named authors also concluded that clinical parity exists in clinical trials comparing atomoxetine and methylphenidate Inhibitors,research,lifescience,medical when confounders are addressed [Bushe and Savill, 2011]. Despite atomoxetine having an onset of action on core ADHD symptoms that commences within the first few weeks, there is increasing this website evidence that the maximal efficacy may not be seen for 10–12 weeks, and there is some evidence from pooled analyses showing a 96% probability of robust improvement at only 52 weeks [Dickson et al. 2011; Montoya et al. 2009; Svanborg et al. 2009]. In clinical usage this may mean that adverse effects are reported earlier than improvement can be measured and consequently treatment could potentially be discontinued early either due to apparent lack of efficacy or adverse events. Adverse events are common in atomoxetine- and placebo-treated cohorts. For example, in a 12-week placebo-controlled trial in a treatment-naïve population, decreased appetite was reported in 27% of patients on atomoxetine and 7.8% of those on placebo [Montoya et al. 2009] (Table 1).