title: Loperamide overdose-induced catatonia: potential role of brain opioid system and P-glycoprotein.
abstract: OBJECTIVE
  Catatonic features are observed in several psychiatric illnesses but can also be found following substance misuse. Loperamide is an anti-diarrhoeal medication that acts on opioid receptors in the intestine, reducing peristalsis. It is normally unable to pass through the intestinal wall or the blood-brain barrier; however, high dosages can in fact induce the effects on the central nervous system.
  
  
  METHODS
  We describe the case of a 20-year-old man who presented with severe catatonia following excessive intake of loperamide, fully remitted with lorazepam.
  
  
  CONCLUSIONS
  We speculate on a possible increase of loperamide's bioavailability after overdose owing to reduced expression and functioning of P-glycoprotein.
authors.affiliation: 1 Department of Clinical and Experimental Medicine, University of Messina, via Consolare Valeria, 1, 98125, Messina, Italy.
authors.forename: Enrica
authors.initials: E
authors.lastname: Di Rosa
authors.affiliation: 2 Department of Neurosciences, University of Messina, via Consolare Valeria, 1, 98125, Messina, Italy.
authors.forename: Antonio E
authors.initials: AE
authors.lastname: Di Rosa
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism; D000930:Antidiarrheals / Q000009:adverse effects*; D001921:Brain / Q000187:drug effects*; D002389:Catatonia / Q000139:chemically induced*; D062787:Drug Overdose / Q000503:physiopathology*; D006801:Humans; D008139:Loperamide / Q000009:adverse effects*; D008297:Male; D011957:Receptors, Opioid / Q000819:agonists; D055815:Young Adult
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000930:Antidiarrheals; D011957:Receptors, Opioid; D008139:Loperamide