title: Colonic transit diagnostic test shows significant gastrointestinal hypomotility in clozapine-treated patients in comparison with subjects treated with other antipsychotics.
abstract: BACKGROUND
  Constipation occurs in 25-60% of the subjects during administration of the antipsychotic drug (AP) clozapine (CLZ).
  
  
  METHODS
  We used a colonic transit diagnostic test that quantifies in a single abdominal X-ray the number of silver O-ring markers out of 25 units ingested five days before. The quantity of markers is directly proportional to the degree of gastrointestinal hypomotility, and elimination of over 80% of the markers is considered normal. The test was applied to three groups of AP-treated subjects for at least three consecutive months: CLZ alone (n=45), CLZ+Other APs (n=28), and Other APs (n=64).
  
  
  RESULTS
  The number of remaining markers at day 5 (mean±S.D.) was significantly higher in the CLZ alone (10.8±10.6) and in the CLZ+Other APs (9.7±9.7) groups than in the Other AP group (4.5±6.7), Kruskal-Wallis test: p=0.004. No significant associations were found between the number of markers, age, AP dose and treatment duration. All subjects who passed <80% of markers - which approximately corresponds to the 60th percentile of marker elimination - showed a scattered marker distribution along the colon, thus suggesting colon inertia. In subjects with hypomotility, 38.5% of the CLZ group, 25% of the CLZ+Other APs group, and 25% of the Other APs group were negative for the Rome III clinical criteria of constipation, thus showing objective, not subjective, hypomotility.
  
  
  CONCLUSIONS
  This study objectively confirms significant gastrointestinal hypomotility associated with CLZ administration.
authors.affiliation: Department of Physiology, Los Andes University Medical School, Av. Tulio Febres Cordero, Mérida 5101-A, Venezuela. Electronic address: trinbap@yahoo.com.
authors.forename: Trino
authors.initials: T
authors.lastname: Baptista
authors.affiliation: Clinical Investigation Institute "Dr. Américo Negrette", Zulia University Medical School, Maracaibo, Venezuela.
authors.forename: Edgardo
authors.initials: E
authors.lastname: Carrizo
authors.affiliation: Clinical Investigation Institute "Dr. Américo Negrette", Zulia University Medical School, Maracaibo, Venezuela.
authors.forename: Erika
authors.initials: E
authors.lastname: Fernandez
authors.affiliation: Clinical Investigation Institute "Dr. Américo Negrette", Zulia University Medical School, Maracaibo, Venezuela.
authors.forename: Lisette
authors.initials: L
authors.lastname: Connell
authors.affiliation: Center for the Attention of Schizophrenics and their Families (CATESFAM), Maracaibo, Venezuela.
authors.forename: Mercedes
authors.initials: M
authors.lastname: Servigna
authors.affiliation: Clinical Investigation Institute "Dr. Américo Negrette", Zulia University Medical School, Maracaibo, Venezuela.
authors.forename: Agner
authors.initials: A
authors.lastname: Parra
authors.affiliation: Clinical Investigation Institute "Dr. Américo Negrette", Zulia University Medical School, Maracaibo, Venezuela.
authors.forename: Jesus
authors.initials: J
authors.lastname: Quintero
authors.affiliation: Department of Psychiatry, Los Andes University Medical School, Mérida, Venezuela.
authors.forename: Albis
authors.initials: A
authors.lastname: Pabón
authors.affiliation: Department of Psychiatry, Los Andes University Medical School, Mérida, Venezuela.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Sandia
authors.affiliation: Department of Psychiatry, Los Andes University Medical School, Mérida, Venezuela.
authors.forename: Euderruh
authors.initials: E
authors.lastname: Uzcáteguid
authors.affiliation: Department of Psychiatry, Los Andes University Medical School, Mérida, Venezuela.
authors.forename: Ana
authors.initials: A
authors.lastname: Serrano
authors.affiliation: Department of Chemistry, Bioanalysis Section, Zulia University Medical School, Maracaibo, Venezuela.
authors.forename: Natacha
authors.initials: N
authors.lastname: Pirela
authors.affiliation: Maracaibo University Hospital, Maracaibo, Venezuela.
authors.forename: Lisbeth
authors.initials: L
authors.lastname: Villarreal
mesh_terms: D000328:Adult; D014150:Antipsychotic Agents / Q000009:adverse effects* / Q000627:therapeutic use; D001714:Bipolar Disorder / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000503:physiopathology; D003024:Clozapine / Q000009:adverse effects* / Q000627:therapeutic use; D003248:Constipation / Q000139:chemically induced / Q000000981:diagnostic imaging / Q000503:physiopathology; D003938:Diagnostic Techniques, Digestive System; D005260:Female; D041981:Gastrointestinal Tract / Q000000981:diagnostic imaging* / Q000187:drug effects* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011860:Radiography, Abdominal / Q000379:methods; D012559:Schizophrenia / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000503:physiopathology; D018030:Silver Compounds
chemical_list: D014150:Antipsychotic Agents; D018030:Silver Compounds; D003024:Clozapine
keywords: Atypical antipsychotics; Clozapine; Constipation; Rome criteria