title: Severe acquired hemophilia with factor VIII inhibition associated with acetaminophen and chlorpheniramine.
abstract: OBJECTIVE
  To report a case of acquired hemophilia with a high-titer factor VIII inhibitor associated with the use of acetaminophen and chlorpheniramine in combination.
  
  
  METHODS
  An 83-year-old woman presented with a severe bleeding disorder 2 weeks after she was prescribed acetaminophen and chlorpheniramine for treatment of a flu-like illness. Laboratory studies showed severe anemia with greatly reduced factor VIII activity and the presence of a high-titer factor VIII inhibitor at 228 Bethesda units. Treatment with high-dose corticosteroids, transfusion of several units of red blood cells, and repeated infusions of factor VIII bypassing activity was successful. Complete clinical and laboratory remission was achieved after 4 weeks of treatment. Use of the Naranjo probability scale suggested a possible association between this adverse event and treatment with acetaminophen and chlorpheniramine.
  
  
  CONCLUSIONS
  Acquired hemophilia due to factor VIII inhibitor(s) has been associated with the use of drugs such as thioxanthenes, interferon, and fludarabine. As of this writing, to the best of our knowledge, no other case has been reported among patients receiving acetaminophen or chlorpheniramine.
  
  
  CONCLUSIONS
  We suggest that acquired hemophilia due to factor VIII inhibitor(s) should be considered in the appropriate setting when patients present with unexplained and even minor bleeding while on treatment with acetaminophen or chlorpheniramine alone or combined.
authors.affiliation: Department of Internal Medicine, San Camillo Hospital, Rome, Italy. gfamularo@scamilloforlanini.rm.it
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Famularo
authors.forename: Silvia
authors.initials: S
authors.lastname: De Maria
authors.forename: Giovanni
authors.initials: G
authors.lastname: Minisola
authors.forename: Giulio Cesare
authors.initials: GC
authors.lastname: Nicotra
mesh_terms: D000082:Acetaminophen / Q000009:adverse effects*; D000368:Aged; D000369:Aged, 80 and over; D018712:Analgesics, Non-Narcotic / Q000009:adverse effects*; D001779:Blood Coagulation Factors / Q000627:therapeutic use; D002744:Chlorpheniramine / Q000009:adverse effects*; D005169:Factor VIII / Q000037:antagonists & inhibitors*; D005260:Female; D006467:Hemophilia A / Q000188:drug therapy / Q000209:etiology*; D006634:Histamine H1 Antagonists / Q000009:adverse effects*; D006801:Humans; D013256:Steroids / Q000627:therapeutic use
chemical_list: D018712:Analgesics, Non-Narcotic; D001779:Blood Coagulation Factors; D006634:Histamine H1 Antagonists; D013256:Steroids; D000082:Acetaminophen; C025667:prothrombin complex concentrates; D002744:Chlorpheniramine; D005169:Factor VIII