title: Effect of loxapine on peripheral dopamine-like and serotonin receptors in patients with schizophrenia.
abstract: OBJECTIVE
  To investigate the effect of loxapine on peripheral dopamine D2-like and serotonin receptor binding and on psychotic symptoms.
  
  
  METHODS
  Patients (n = 24) meeting the diagnostic criteria of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision, for schizophrenia were selected from an outpatient clinic (age range 18-70 yr).
  
  
  METHODS
  Patients were given loxapine (dose determined by a physician) for a period of 12 weeks. There were clinic visits at before treatment began and at 6 weeks and 12 weeks of treatment. Scores on a variety of efficacy and safety scales were recorded at each visit, and blood was drawn for receptor assays.
  
  
  RESULTS
  Patients showed significant improvement on most psychiatric assessment scales after 6 and 12 weeks of treatment with loxapine, and both lymphocyte D2-like and 5-HTL2A platelet receptor binding were down-regulated after 6 and 12 weeks. The degree of receptor down-regulation was not significantly correlated with improvements in psychotic symptoms, however.
  
  
  CONCLUSIONS
  Loxapine down-regulated both lymphocyte D2-like and platelet 5-HT2A receptors to the same extent, suggesting that both receptors are involved in the mechanism of action of loxapine in patients with schizophrenia.
authors.affiliation: Department of Psychiatry, Queen's University, Kingston, Ont. singha@post.queensu.ca
authors.forename: Amarendra N
authors.initials: AN
authors.lastname: Singh
authors.forename: Cia
authors.initials: C
authors.lastname: Barlas
authors.forename: Huma
authors.initials: H
authors.lastname: Saeedi
authors.forename: Ram K
authors.initials: RK
authors.lastname: Mishra
mesh_terms: D000328:Adult; D014150:Antipsychotic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism; D018492:Dopamine Antagonists / Q000009:adverse effects / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation / Q000187:drug effects; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008152:Loxapine / Q000009:adverse effects / Q000627:therapeutic use*; D008214:Lymphocytes / Q000187:drug effects / Q000378:metabolism; D008238:Lysergic Acid Diethylamide / Q000493:pharmacokinetics; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011569:Psychiatric Status Rating Scales; D011869:Radioligand Assay; D044402:Receptor, Serotonin, 5-HT2A; D017448:Receptors, Dopamine D2 / Q000187:drug effects* / Q000502:physiology; D011985:Receptors, Serotonin / Q000187:drug effects* / Q000502:physiology; D012559:Schizophrenia / Q000175:diagnosis / Q000188:drug therapy* / Q000503:physiopathology; D012565:Schizophrenic Psychology; D016896:Treatment Outcome
chemical_list: D014150:Antipsychotic Agents; D018492:Dopamine Antagonists; D044402:Receptor, Serotonin, 5-HT2A; D017448:Receptors, Dopamine D2; D011985:Receptors, Serotonin; D008238:Lysergic Acid Diethylamide; D008152:Loxapine