title: Normalization of plasma vitamin B12 concentration by intranasal hydroxocobalamin in vitamin B12-deficient patients.
abstract: OBJECTIVE
  Patients with previous stomach and terminal ileum resections are often treated with intramuscular vitamin B12 injections. Disadvantages are, on a worldwide scale, the frequent need for medical personnel to administer injections and the sometimes painful way of application. This study was designed to investigate the feasibility of intranasal hydroxocobalamin suppletion in cobalamin-deficient patients and to assess whether intranasal hydroxocobalamin application could be an alternative for intramuscular injection.
  
  
  METHODS
  Six patients with plasma cobalamin concentrations of < 200 ng/L were recruited. A dose of 1500 micrograms hydroxocobalamin was applied intranasally at days 0, 14, and 21. Plasma cobalamin concentrations were determined 1 hour after hydroxocobalamin application and on days 0, 7, 21, 28, and 35.
  
  
  RESULTS
  All patients showed substantial increase of cobalamin concentrations 1 hour after intranasal application. In these 6 patients, there was an eightfold increase of mean baseline cobalamin concentrations. All patients showed a sustained increase of baseline cobalamin concentrations 1 week after prior intranasal application of hydroxocobalamin. No side effects were noted.
  
  
  CONCLUSIONS
  Intranasal application of hydroxocobalamin in cobalamin-deficient patients results in fast nasal absorption and leads to sustained increase of baseline cobalamin concentrations.
authors.affiliation: Department of Gastroenterology, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: W B
authors.initials: WB
authors.lastname: Slot
authors.forename: F W
authors.initials: FW
authors.lastname: Merkus
authors.forename: S J
authors.initials: SJ
authors.lastname: Van Deventer
authors.forename: G N
authors.initials: GN
authors.lastname: Tytgat
mesh_terms: D000281:Administration, Intranasal; D004305:Dose-Response Relationship, Drug; D006397:Hematinics / Q000008:administration & dosage / Q000627:therapeutic use*; D006801:Humans; D006879:Hydroxocobalamin / Q000008:administration & dosage / Q000627:therapeutic use*; D011863:Radioimmunoassay; D013997:Time Factors; D014805:Vitamin B 12 / Q000097:blood*; D014806:Vitamin B 12 Deficiency / Q000097:blood* / Q000188:drug therapy*
chemical_list: D006397:Hematinics; D014805:Vitamin B 12; D006879:Hydroxocobalamin