Bernhard 2009.

Methods	A patient report of a 4‐year‐old boy with T‐cell acute lymphoblastic leukemia and in maintenance therapy with purinethol and methotrexate experiencing a hepatotoxic reaction after onset of methylphenidate treatment
Participants	Diagnosis of ADHD: DSM‐IV (subtype: hyperactive‐impulsive) Age: 4 years and 6 months old IQ: unknown Sex: male Ethnicity: not stated Country: Germany Setting: outpatient clinic Comorbidity: T‐ALL; severe damage to white matter induced by chemo‐ and radiotherapy Comedication: purinethol and methotrexate Sociodemographics: unknown
Interventions	Methylphenidate type: short acting Ritalin Methylphenidate dosage: 10 mg, 0.6 mg/kg Administration schedule: once daily in the morning Duration of treatment: 3 weeks titration. 6 weeks treatment in total. Treatment compliance: not stated
Outcomes	Serious adverse events: A hepatotoxic reaction: liver enzymes were elevated prior to therapy. Vomiting starting 5 weeks after onset of methylphenidate therapy and increased within the next 3 days. Abdominal pain increased in intensity. Liver transaminases elevated over 30 times of the normal level, CK level also increased
Notes	Key conclusions of the study authors: hepatotoxicity of methylphenidate can be considered minimal. However, methylphenidate therapy in children with prior or possible hepatic damage should be monitored clinically and by laboratory testing in short intervals Comments from the study authors: liver enzymes elevated prior to treatment Funding/vested interests: none Authors' affiliations: Hospital for Children and Adolescents, University of Leipzig, Leipzig, Germany