title: Effect of Adenine on Clozapine-induced Neutropenia in Patients with Schizophrenia: A Preliminary Study.
abstract: OBJECTIVE
  This study examined the utility of adenine for preventing clozapine-induced neutropenia.
  
  
  METHODS
  This retrospective study examined the effect of adenine on clozapine-induced neutropenia in patients with treatment- resistant schizophrenia and was conducted at Okehazama Hospital in Japan from July 2010 to June 2013. Adenine was available for use from June 2011 onwards. Twenty-one patients started receiving clozapine treatment from July 2010 to April 2011 (the pre-adenine adoption group), and 47 patients started receiving it from May 2011 to June 2013 (the post-adenine adoption group). The effects of adenine were assessed based on changes in the patients' leukocyte counts and the frequency of treatment discontinuation due to clozapine-induced neutropenia.
  
  
  RESULTS
  Sixty-eight patients were treated with clozapine from July 2010 to June 2013. Of the 21 patients in the pre-adenine adoption group, 4 discontinued treatment due to clozapine-induced neutropenia, whereas only 2 of the 47 patients in the post-adenine adoption group discontinued treatment. The frequency of treatment discontinuation due to clozapine-induced neutropenia was significantly lower in post-adenine adoption group than in the pre-adenine adoption group (p=0.047).
  
  
  CONCLUSIONS
  Adenine decreased the frequency of treatment discontinuation due to clozapine-induced neutropenia. Our data suggest that combined treatment with clozapine and adenine is a safe and effective strategy against treatment-resistant schizophrenia.
authors.affiliation: Department of Psychiatry, Okehazama Hospital, Toyoake, Aichi, Nagoya, Japan.|Office of Clinical Pharmacy Practice and Health Care Management, Faculty of Pharmacy, Meijo University, Nagoya, Japan.
authors.forename: Ippei
authors.initials: I
authors.lastname: Takeuchi
authors.affiliation: Department of Psychiatry, Okehazama Hospital, Toyoake, Aichi, Nagoya, Japan.
authors.forename: Taro
authors.initials: T
authors.lastname: Kishi
authors.affiliation: Office of Clinical Pharmacy Practice and Health Care Management, Faculty of Pharmacy, Meijo University, Nagoya, Japan.
authors.forename: Manako
authors.initials: M
authors.lastname: Hanya
authors.affiliation: Department of Psychiatry, Okehazama Hospital, Toyoake, Aichi, Nagoya, Japan.
authors.forename: Junji
authors.initials: J
authors.lastname: Uno
authors.affiliation: Department of Psychiatry, Okehazama Hospital, Toyoake, Aichi, Nagoya, Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Fujita
authors.affiliation: Office of Clinical Pharmacy Practice and Health Care Management, Faculty of Pharmacy, Meijo University, Nagoya, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kamei
keywords: Adenine; Clozapine; Neutropenia; Schizophrenia; Side-effect