Methylphenidate misuse in adult patients and the impact of therapeutic use

Abstract

Objective: Methylphenidate (MPH) prescription rates for adults increase, but the extent of a parallel rise in toxic exposures and their causes and distribution between different MPH trade names are unexplored. Method: We retrospectively analyzed adult MPH exposures reported to the Danish Poison Information Centre from January 2006 to July 2012 and the association with MPH sales and the number of patients prescribed MPH. Results: Of the 394 exposures (57% males, median age 27 years) reported, MPH status was available in 249 of whom 65.5% were prescribed MPH. Exposure was in 54% motivated by suicidal attempt and in 40% by recreational use (based on 375 cases). Exposure was dominated by one trade name and exposure incidence correlated significantly with sales (  p = 0.001) and prevalence of MPH-treated patients (  p = 0.0008). Conclusions: The increase in MPH exposures parallels the prescription rates (particularly Ritalin®/Ritalin® Uno). Most exposures were intentional and motivated by suicide attempts or recreational use.