title: Asterixis and toxic encephalopathy induced by gabapentin.
abstract: OBJECTIVE
  To date, only one case of asterixis associated with the use of gabapentin (GBT) has been reported. No data, instead, are available on the occurrence of asterixis related to a dementing encephalopathy during GBT therapy in the elderly.
  
  
  METHODS
  Case reports of two elderly patients, one with asterixis, the other with asterixis and encephalopathy, associated with the use of GBT, as adjunctive therapy, at dosages of 900 to 3600 mg/day are given. In one patient, GBT was added to oxcarbazepine (OXCBZ).
  
  
  RESULTS
  Both patients experienced resolution of the clinically apparent asterixis, and of the toxic encephalopathy, on discontinuation or reduction of GBT dosages. One patient developed asterixis after drug rechallenge. In the patient on OXCBZ, the analysis of the electromyogram (EMG) activity showed the occurrence of a subclinical asterixis.
  
  
  CONCLUSIONS
  Our study indicates that high doses of GBT may induce asterixis related to a reversible encephalopathy. Low doses of GBT, instead, may induce a disabling asterixis when given in combination with OXCBZ because of a synergistic interaction between these drugs.
authors.affiliation: Neurological Clinic, University of Sassari, Viale San Pietro, 10, 07100 Sassari, Italy. gpsechi@ssmain.uniss.it
authors.forename: GianPietro
authors.initials: G
authors.lastname: Sechi
authors.forename: Bastianino
authors.initials: B
authors.lastname: Murgia
authors.forename: GianFranco
authors.initials: G
authors.lastname: Sau
authors.forename: Luigi
authors.initials: L
authors.lastname: Peddone
authors.forename: Antonella
authors.initials: A
authors.lastname: Tirotto
authors.forename: Marianna
authors.initials: M
authors.lastname: Barrocu
authors.forename: Giulio
authors.initials: G
authors.lastname: Rosati
mesh_terms: D000085:Acetates / Q000009:adverse effects* / Q000627:therapeutic use; D000368:Aged; D000588:Amines; D000927:Anticonvulsants / Q000009:adverse effects* / Q000627:therapeutic use; D001921:Brain / Q000473:pathology; D001927:Brain Diseases / Q000139:chemically induced* / Q000473:pathology / Q000503:physiopathology*; D002220:Carbamazepine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D003509:Cyclohexanecarboxylic Acids; D004409:Dyskinesia, Drug-Induced / Q000503:physiopathology*; D004576:Electromyography; D020329:Essential Tremor / Q000150:complications / Q000188:drug therapy; D005260:Female; D000077206:Gabapentin; D006801:Humans; D008279:Magnetic Resonance Imaging; D009044:Motor Cortex / Q000503:physiopathology; D000078330:Oxcarbazepine; D005680:gamma-Aminobutyric Acid
chemical_list: D000085:Acetates; D000588:Amines; D000927:Anticonvulsants; D003509:Cyclohexanecarboxylic Acids; D002220:Carbamazepine; D005680:gamma-Aminobutyric Acid; D000077206:Gabapentin; D000078330:Oxcarbazepine