title: A clinical validation study for application of DBS in therapeutic drug monitoring of antidepressants.
abstract: BACKGROUND
  A bridging study of plasma and DBS concentrations for therapeutic drug monitoring of antidepressants was performed. RESULTS & METHODOLOGY: Potassium-based hematocrit analysis was included. In addition, we defined acceptance criteria based on the differences between individual data points of plasma and DBS concentrations. These criteria were applied to test acceptability of error found in predicted nortriptyline plasma concentrations. Potassium-based hematocrit predicted a negative bias for DBS concentrations of amitriptyline, but not for the other compounds. To predict plasma concentrations of antidepressants based on DBS concentrations, a factor of 0.8, 0.65, 0.84 and 0.78 was found for nortriptyline, desmethylclomipramine, venlafaxine and desmethylvenlafaxine, respectively.
  
  
  CONCLUSIONS
  Application of the factor and newly formulated acceptance criteria demonstrated prediction of nortriptyline plasma concentrations based on DBS concentrations.
authors.affiliation: Department of Pharmacy, Section Pharmacotherapy & Pharmaceutical Care, University of Groningen, 9712 CP Groningen, The Netherlands.
authors.forename: Elizabeth J J
authors.initials: EJ
authors.lastname: Berm
authors.affiliation: Department of Pharmacy, Section Pharmacotherapy & Pharmaceutical Care, University of Groningen, 9712 CP Groningen, The Netherlands.
authors.forename: Blessing
authors.initials: B
authors.lastname: Odigie
authors.affiliation: Unit PharmacoEpidemiology & PharmacoEconomics (PE2), Department of Pharmacy, University of Groningen, 9712 CP Groningen, The Netherlands.
authors.forename: Maarten J
authors.initials: MJ
authors.lastname: Bijlsma
authors.affiliation: Department of Pharmacy, Section Pharmacotherapy & Pharmaceutical Care, University of Groningen, 9712 CP Groningen, The Netherlands.|Department of Clinical Pharmacy & Pharmacology, University Medical Center Groningen, University of Groningen, 9712 CP Groningen, The Netherlands.
authors.forename: Bob
authors.initials: B
authors.lastname: Wilffert
authors.affiliation: Department of Clinical Pharmacy & Pharmacology, University Medical Center Groningen, University of Groningen, 9712 CP Groningen, The Netherlands.
authors.forename: Daan J
authors.initials: DJ
authors.lastname: Touw
authors.affiliation: Laboratory for Drug Analysis & Toxicology, Diaconessen Hospital Meppel & Bethesda Hospital Hoogeveen, Meppel, The Netherlands.
authors.forename: Jan G
authors.initials: JG
authors.lastname: Maring
mesh_terms: D000928:Antidepressive Agents / Q000097:blood*; D059788:Dried Blood Spot Testing / Q000379:methods*; D016903:Drug Monitoring / Q000379:methods*; D006400:Hematocrit; D006801:Humans; D057230:Limit of Detection; D011188:Potassium / Q000737:chemistry
chemical_list: D000928:Antidepressive Agents; D011188:Potassium
keywords: DBS; antidepressants; clinical validation; plasma; therapeutic drug monitoring