Grossman 1985.

Methods	A patient report on methylphenidate and idiopathic thrombocytopenic purpura (ITP)
Participants	ICD‐9 diagnosis of ADHD (subtype: not known) Age: 7 years old IQ: > 70 Sex: female Ethnicity: white   Country: USA Comorbidity: none Comedication: not stated Sociodemographics: not stated
Interventions	Methylphenidate type: not stated Methylphenidate dosage: 10 mg Administration schedule: twice daily Duration of intervention: 7 months Treatment compliance: not stated
Outcomes	Serious adverse events: Idiopathic thrombocytopenic purpura: physical examination at the Pediatric Outpatient Department found countless petechiae over the entire dermal surface, most concentrated over her buttocks. Numerous areas of purpura were noted, especially over her buttocks and extremities. Multiple areas of buccal mucosal and gingival bleeding with a large haematoma presented on the left lateral surface of her tongue. Clotted blood was seen in her nostrils and ear canals bilaterally. Bone marrow aspiration showed normal to increased megakaryocytes with normal red and white cell precursors. Methylphenidate was stopped and the patient was admitted. After 1 week of treatment for the condition her petechia had begun to fade. She did not start on methylphenidate again. There has been no recurrence of petechiae or bruising 1 year later
Notes	Ethics approval: not stated Funding/vested interests: not stated Key conclusions of study authors: it is hoped that the report of this case will stimulate others to report their experience, or lack thereof, regarding the association of methylphenidate and idiopathic thrombocytopenic purpura. Because of the importance of this drug to the management of certain children with attention deficit disorder and its widespread use in thousands of children, it seems important to justify with data the current precaution that "periodic CBC, differential and platelet counts are advised during prolonged therapy" or eliminate the precaution as a recommendation to clinicians Comments from the study authors: the authors describe, that the patient had a mild upper respiratory tract infection 2 weeks prior to the symptoms of ITP. They describe, it is highly possible that in the case just presented the aetiology of the patient's idiopathic thrombocytopenic purpura may well have been her preceding upper respiratory tract infection rather than the methylphenidate, which she had taken without difficulty for 7 months prior to the onset of her haematologic disorder Supplemental information regarding ADHD diagnosis received through personal correspondence with the authors in July 2013 (Grossman 2013 [pers comm])