Are there any potentially dangerous pharmacological effects of combining ADHD medication with alcohol and drugs of abuse? A systematic review of the literature

Background: Among young people up to 18 years of age, approximately 5 % have attention deficit hyperactivity disorder (ADHD), many of whom have symptoms persisting into adulthood. ADHD is associated with increased risk of co-morbid psychiatric disorders, including substance misuse. Many will be prescribed medication, namely methylphenidate, atomoxetine, dexamphetamine and lisdexamfetamine. If so, it is important to know if interactions exist and if they are potentially toxic. Methods: Three databases (Medline, EMBASE and PsychINFO) from a 22 year period (1992-June 2014) were searched systematically. Key search terms included alcohol, substance related disorders, methylphenidate, atomoxetine, dexamphetamine, lisdexamfetamine, and death, which identified 493 citations (344 after removal of duplicates). The eligibility of each study was assessed jointly by two investigators, leaving 20 relevant articles. Results: We identified only a minimal increase in side-effects when ADHD medication (therapeutic doses) was taken with alcohol. None of the reviewed studies showed severe sequelae among those who had overdosed on ADHD medication and other coingestants, including alcohol. Conclusions: The numbers across all the papers studied remain too low to exclude uncommon effects. Also, studies of combined effects with novel psychoactive substances have not yet appeared in the literature. Nevertheless, no serious sequelae were identified from combining ADHD medication with alcohol/illicit substances from the pre-novel psychoactive substance era.