title: Plasma haloperidol levels and clinical effects in schizophrenia and schizoaffective disorder.
abstract: BACKGROUND
  Plasma haloperidol levels between 5 and 11 ng/mL may be clinically optimal for acutely exacerbated schizophrenia, but the evidence for this therapeutic window has been inconsistent.
  
  
  METHODS
  Haloperidol was administered in a double-blind manner during two consecutive 3-week experimental periods to 65 patients with acutely exacerbated schizophrenia or schizoaffective disorder. Two plasma levels were targeted: "low" (2 ng/mL) and "moderate" (10 ng/mL). The subjects were randomly assigned to four treatment sequences (low-low, low-moderate, moderate-moderate, or moderate-low).
  
  
  RESULTS
  In the first 3 weeks, the antipsychotic efficacy of haloperidol increased with plasma levels up to approximately 12 ng/mL. In the second 3 weeks, decrease of plasma levels reduced negative symptoms.
  
  
  CONCLUSIONS
  For most patients, plasma levels not exceeding 12 ng/mL yield the best results in the first 3 weeks of treatment. Subsequent lowering of the plasma levels may improve negative symptoms.
authors.affiliation: Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY, USA.
authors.forename: J
authors.initials: J
authors.lastname: Volavka
authors.forename: T B
authors.initials: TB
authors.lastname: Cooper
authors.forename: P
authors.initials: P
authors.lastname: Czobor
authors.forename: M
authors.initials: M
authors.lastname: Meisner
mesh_terms: D000328:Adult; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005260:Female; D006220:Haloperidol / Q000097:blood* / Q000627:therapeutic use; D006760:Hospitalization; D006801:Humans; D008297:Male; D011336:Probability; D011618:Psychotic Disorders / Q000097:blood / Q000188:drug therapy* / Q000523:psychology; D012559:Schizophrenia / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy*; D012565:Schizophrenic Psychology; D016896:Treatment Outcome
chemical_list: D006220:Haloperidol