title: Cross Hypersensitivity Syndrome between Phenytoin and Carbamazepine.
abstract: OBJECTIVE
  To evaluate the incidence of cross anticonvulsant hypersensitivity syndrome (AHS) between phenytoin (PHT) and carbamazepine (CBZ) in hospitalized patients.
  
  
  METHODS
  Retrospective chart review about the cross AHS was retrieved from pharmacy adverse drug reaction program from 1998 to 2002 in a 450-bed teaching hospital.
  
  
  METHODS
  AHS was defined as the appearance of at least two symptoms with the first anticonvulsant drug (ACD). Cross AHS was considered if after withdrawal of a first ACD because of hypersensitivity symptoms, a new episode with similar or new symptoms appeared after exposure to a second ACD. The following symptoms were considered- rash, fever, hepatotoxicity, lymphadenopathies or hematological disturbances.
  
  
  RESULTS
  Cross AHS between PHT and CBZ was observed in nine cases (45). After the cross-reaction event, four of them were treated with valproic acid, two with vigabatrin, two with phenobarbital and one with no treatment without developing further AHS.
  
  
  CONCLUSIONS
  AHS is a severe complication of aromatic ACD that can compromise the future choice of therapy. Because of the high incidence of clinical cross-reaction between these two drugs, non-aromatic ACD alternatives, must be considered.
authors.affiliation: Hospital Severo Ochoa, Avda Orellana s/n, 28911, Leganés, Madrid, Spain. nereamoyano@hotmail.com
authors.forename: Nerea Moyano
authors.initials: NM
authors.lastname: Sierra
authors.forename: Benito
authors.initials: B
authors.lastname: García
authors.forename: Javier
authors.initials: J
authors.lastname: Marco
authors.forename: Susana
authors.initials: S
authors.lastname: Plaza
authors.forename: Francisco
authors.initials: F
authors.lastname: Hidalgo
authors.forename: Teresa
authors.initials: T
authors.lastname: Bermejo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000927:Anticonvulsants / Q000009:adverse effects*; D002220:Carbamazepine / Q000009:adverse effects*; D002648:Child; D002675:Child, Preschool; D003429:Cross Reactions; D004342:Drug Hypersensitivity / Q000175:diagnosis / Q000201:enzymology / Q000453:epidemiology*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D010672:Phenytoin / Q000009:adverse effects*; D012189:Retrospective Studies
chemical_list: D000927:Anticonvulsants; D002220:Carbamazepine; D010672:Phenytoin