title: Plasma amisulpride in relation to prescribed dose, clozapine augmentation, and other factors: data from a therapeutic drug monitoring service, 2002-2010.
abstract: OBJECTIVE
  This study aimed to investigate the effect of dose and other factors on plasma amisulpride concentrations in clinical practice.
  
  
  METHODS
  Amisulpride therapeutic drug monitoring data 2002-2010 have been studied.
  
  
  RESULTS
  There were 296 samples (196 adult patients). Amisulpride was not detected in 10% of samples. In the remainder, the mean plasma amisulpride in relation to the prescribed dose (mg/day) was as follows: 100-200 (111 µg/L), 201-400 (254 µg/L), 400-800 (421 µg/L), and 800-1200 (494 µg/L). For prescribed doses up to 800 mg/day, only 51% of results were within 100-319 µg/L. There were no significant sex differences in mean plasma amisulpride or mean dose. The mean plasma amisulpride, but not the dose, was significantly higher in smokers. Linear regression analysis showed that dose explained only 42% of the variation in plasma amisulpride after log(10) transformation of both variables. There was no significant difference in the mean dose or mean plasma amisulpride in patients co-prescribed clozapine as compared with the remaining samples.
  
  
  CONCLUSIONS
  In practice, dose is a poor predictor of plasma amisulpride concentration. Therapeutic drug monitoring may not only help assess adherence, but also guide dosage.
authors.affiliation: Toxicology Unit, Department of Clinical Biochemistry, King's College Hospital NHS Foundation Trust, London, UK.
authors.forename: Sally V J
authors.initials: SV
authors.lastname: Bowskill
authors.forename: Maxine X
authors.initials: MX
authors.lastname: Patel
authors.forename: Simon A
authors.initials: SA
authors.lastname: Handley
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Flanagan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000077582:Amisulpride; D014150:Antipsychotic Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D003024:Clozapine / Q000008:administration & dosage / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D016903:Drug Monitoring / Q000379:methods*; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D012907:Smoking / Q000453:epidemiology; D013469:Sulpiride / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D055815:Young Adult
chemical_list: D014150:Antipsychotic Agents; D013469:Sulpiride; D000077582:Amisulpride; D003024:Clozapine