title: Serotonin syndrome associated with clozapine withdrawal.
abstract: OBJECTIVE
  We describe a case of serotonin syndrome secondary to clozapine withdrawal and concomitant use of citalopram hydrobromide, a phenomenon that has been rarely reported.
  
  
  METHODS
  This is a case report of a 47-year-old woman admitted to an academic medical center intensive care unit with coma, hypersalivation, hyperreflexia, and stimulus-induced clonus. The patient received a diagnosis of serotonin syndrome attributed to abrupt clozapine withdrawal with concomitant use of citalopram. She improved only minimally with supportive treatment (intravenous fluids, benzodiazapines, and withdrawal of selective serotonin-reuptake inhibitor) and received cyproheptadine hydrochloride on her third day of symptoms. Four hours after she received the loading dose of cyproheptadine, she was alert and oriented and at her baseline mental status, although some clonus remained.
  
  
  CONCLUSIONS
  Serotonin syndrome can result from the abrupt withdrawal of a 5-hydroxytryptamine receptor 2A antagonist from a treatment regimen that also includes a medication that increases serotonin availability.
authors.affiliation: Department of Pulmonary Critical Care, Boston Medical Center, Boston University School of Medicine, Massachusetts 02118, USA. elizabeth.stevenson@bmc.org
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Stevenson
authors.forename: Frank
authors.initials: F
authors.lastname: Schembri
authors.forename: Deborah M
authors.initials: DM
authors.lastname: Green
authors.forename: Joseph D
authors.initials: JD
authors.lastname: Burns
mesh_terms: D001569:Benzodiazepines / Q000627:therapeutic use; D015283:Citalopram / Q000009:adverse effects* / Q000627:therapeutic use; D003024:Clozapine / Q000009:adverse effects* / Q000627:therapeutic use; D003533:Cyproheptadine / Q000627:therapeutic use; D005260:Female; D006801:Humans; D008875:Middle Aged; D012702:Serotonin Antagonists / Q000009:adverse effects* / Q000627:therapeutic use; D020230:Serotonin Syndrome / Q000139:chemically induced* / Q000188:drug therapy; D017367:Selective Serotonin Reuptake Inhibitors / Q000009:adverse effects* / Q000627:therapeutic use; D013375:Substance Withdrawal Syndrome / Q000150:complications* / Q000188:drug therapy / Q000209:etiology
chemical_list: D001569:Benzodiazepines; D015283:Citalopram; D003024:Clozapine; D003533:Cyproheptadine; D012702:Serotonin Antagonists; D017367:Selective Serotonin Reuptake Inhibitors