Ririe 1997.

Methods	A patient report on unexpected interaction of methylphenidate (Ritalin) with anaesthetic agents
Participants	Diagnosis of ADD/ADHD: DSM‐IV (subtype: not stated) Age: 6 years old IQ: > 70 Sex: male Ethnicity: not stated Country: USA Comorbidity: history of William's syndrome and supravalvar aortic stenosis Comedication: only during anaesthesia: midazolam 20 mg + 10 mg, ketamine 60 mg, Glycopyrrolat IV 0,1 mg, midazolam IV 5 mg Sociodemographics: living at home with parents
Interventions	Immediate release methylphenidate (Ritalin) dosage: 10 mg/day Administration schedule: twice daily Duration of treatment: 2 months Treatment compliance: not stated
Outcomes	Non‐serious adverse events: Difficulty with conscious sedation. No previous problems with sedation. Despite additional oral doses of sedatives the child remained alert and unable to lie still, until intravenous sedative drugs were given. After discharge, the child developed nausea, vomiting, lethargy and dehydration, which led to hospitalisation
Notes	Funding/vested interest/authors' affiliations: Novartis Key conclusions of the study authors: there could be a potential risk of unwanted interactions between methylphenidate and anaesthetic agents. Based on the observations from the patient report, a more detailed and systematic investigation of methylphenidate in patients undergoing anaesthesia or sedation is warranted Comments from the study authors: no previous problems with anaesthesia. The child had no apparent limitations of activity and no cardiac symptoms. We believe that the stimulant effect of methylphenidate may have played a major role in antagonising the sedative effect of the oral midazolam in the clinically recommended doses. The stimulant effect of methylphenidate makes it potentially very difficult to attain a desirable level of sedation without requiring large and potentially unsafe doses of sedative drugs or administration of general anaesthesia. The gastrointestinal side effects of methylphenidate, particularly decreased appetite and nausea and vomiting, may be aggravated by many of the drugs used for sedation or general anaesthesia Supplemental information regarding intellectual function and diagnostic criteria received through personal email correspondence with the authors in October 2013 (Ririe 2013 [pers comm])