title: Methylphenidate intoxications in children and adults: exposure circumstances and evidence-based dose threshold for pre-hospital triage.
abstract: BACKGROUND
  Methylphenidate intoxications mostly have a relatively mild course, although serious complications can occur.
  
  
  OBJECTIVE
  We aimed to characterize methylphenidate exposures and reassess our current dose threshold for hospital referral (2 mg/kg).
  
  
  METHODS
  In a prospective follow-up study, we analysed 364 consecutive methylphenidate exposures that were reported to the Dutch Poisons Information Center. Patients and/or physicians were surveyed by telephone using standardized questionnaires. Three physicians independently scored the observed severity of the intoxication of each patient as 'no/mild' (observation at home) or 'moderate/severe' (hospital referral necessary).
  
  
  RESULTS
  Unintentional exposures (40%) mostly occurred at home involving the patients' own medication or those from a family member. Compared to unintentionally exposed patients, intentionally exposed patients were exposed to relatively high methylphenidate doses (3.1 vs 1.6 mg/kg), more often used immediate release methylphenidate formulations (62 vs 34%) and more frequently had concomitant exposures (71 vs 17%). Severe symptoms like convulsions or coma were reported only in patients with concomitant exposures. Following exposure to methylphenidate only (i.e. no concomitant exposures), the most commonly reported symptoms were dry mucosa, headache, agitation, sleepiness and tachycardia. Our results show that the reported methylphenidate dose is predictive of the observed severity of the intoxication and can therefore aid in pre-hospital triage.
  
  
  CONCLUSIONS
  We increased our current dose threshold for hospital referral from 2 to 3 mg/kg. In addition, we will refer patients at lower doses when clinical symptoms indicate the need for hospital referral. Application of this new dose threshold optimizes triage, thereby reducing unnecessary hospital referral and thus costs, without jeopardising patient safety.
authors: National Poisons Information Center, University Medical Center Utrecht , the Netherlands.
authors: Laura
authors: L
authors: Hondebrink
authors: Saskia J
authors: SJ
authors: Rietjens
authors: Claudine C
authors: CC
authors: Hunault
authors: Rob R
authors: RR
authors: Pereira
authors: Nuriye
authors: N
authors: Kelleci
authors: Gulhan
authors: G
authors: Yasar
authors: Ariam
authors: A
authors: Ghebreslasie
authors: Cindy
authors: C
authors: Lo-A-Foe
authors: Irma
authors: I
authors: De Vries
authors: Jan
authors: J
authors: Meulenbelt
mesh_terms: D000293:Adolescent; D000328:Adult; D000697:Central Nervous System Stimulants / Q000506:poisoning*; D002648:Child; D002675:Child, Preschool; D004305:Dose-Response Relationship, Drug; D004632:Emergency Medical Services; D019317:Evidence-Based Medicine; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008774:Methylphenidate / Q000506:poisoning*; D009426:Netherlands; D011039:Poison Control Centers; D011041:Poisoning / Q000175:diagnosis / Q000209:etiology / Q000628:therapy*; D011446:Prospective Studies; D012017:Referral and Consultation; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D014218:Triage; D055815:Young Adult
chemical_list: D000697:Central Nervous System Stimulants; D008774:Methylphenidate
keywords: ADHD; Abuse; Poisoning; Ritalin; Toxicity