Research Article | J Pharmacol Pharm Res. 2018;1(1):001 | Open Access
Comparison of Dose-Related Reference Ranges with Individual Psychotropic Drug Serum Concentrations in Clinical Practice - AGNP Consensus Guidelines 2011 and 2017
Gudrun Hefner, Martina Hahn, Maria Buenger and Sibylle C. RollPDF
Introduction: In 2017, AGNP Consensus Guidelines were updated with special focus on improved dose-related reference ranges (DRRR). DRRR can be used to identify pharmacokinetic abnormalities in individuals by comparing the expected calculated range with a measured drug concentration. We compared DRRR of the consensus guidelines 2011 and 2017 with drug concentrations in psychiatric patients.
Materials and Methods: Data of 236 psychiatric inpatients whose drug serum concentrations had been measured were retrospectively screened and strongly selected to receive data from “normal” patients without pharmacokinetic abnormalities. For about 68% of the drug concentrations of these patients should be within a valid calculated DRRR. DRRR were calculated according to 2011 and 2017 guidelines.
Results: In total, 78 drug concentrations from 71 patients were available for analysis. Only 33.3% (n=26) of these concentrations were within the DRRR 2011 and 47.4% (n=37) within the DRRR 2017. The validity of calculated DRRR could only be confirmed for venlafaxine in the new guidelines, as 77.8% (n=14) of drug concentrations were between the DRRR, but not be confirmed for duloxetine (n=9) and valproic acid (n=26).
Discussion: The DRRR calculation in the guidelines 2017 was notably improved but further pharmacokinetic data is needed to allow a better “forecast” of the expected drug concentrations in a patient though, allowing a future guideline update to generate more accurate factors for the DRRR calculation. Currently, DRRR can support clinical decision making, but they should be used with caution for several drugs as a rough orienting range.
Keywords: AGNP consensus guidelines; Dose-related reference range; Serum concentration; Therapeutic drug monitoring; Psychiatry; Psychotropic drug
Citation: Hefner G, Hahn M, Buenger M, Roll SC. Comparison of Dose-Related Reference Ranges with Individual Psychotropic Drug Serum Concentrations in Clinical Practice - AGNP Consensus Guidelines 2011 and 2017. J Pharmacol Pharm Res. 2017;1(1):001