Some of these data may also represent important information for the laboratory to judge plausibility of the result. Critical appreciation of the results A pharmacological treatment should be guided by sound clinical

judgment. TDM has to be considered as an additional and useful tool for optimizing therapy. Analytical methods used in the laboratories may differ in their quality. The physician should be aware that some drug levels are not accurately measured, even though most laboratories have introduced a program to measure quality. Indeed, worldwide external quality-control programs show considerable variability between laboratories in Inhibitors,research,lifescience,medical the results

Inhibitors,research,lifescience,medical of analysis of control samples. The physician may obtain discrepant results when a drug was monitored several times in a patient, but analyzed in different laboratories. When comparisons of TDM values obtained from different laboratories are carried out, the clinician should take Inhibitors,research,lifescience,medical into account the units (ng/mL, μg/L, μmol/L, nmol/L) in which the results of the analysis are expressed. Low plasma drug concentrations suggest either irregular intake of the drug or ultrarapid metabolism, and in this situation, a pharmacogenetic test may be indicated. In the first case, TDM should be repeated in order to verify compliance. These examples show that it may be advantageous for the clinician to collaborate with a TDM laboratory that offers pharmacological consultation.

TDM interpretation and treatment of patients A TDM result represents a guide to adjust the treatment of the individual patient, but expert interpretation and adequate Inhibitors,research,lifescience,medical use of this pharmacokinetic data are mandatory for an optimal clinical benefit. Reporting of results and inclusion of dose recommendations and other comments by the laboratory must be guided by the best available evidence. LY2835219 However, the laboratory Inhibitors,research,lifescience,medical has only limited knowledge of the clinical context. The physician should also take into consideration whether the “reference plasma concentrations range” reflects only “drug plasma concentrations at clinically relevant doses” (Table III) or whether they are “therapeutic ranges” (Table IV). Information on the level Resminostat of recommendation for TDM of the particular drug may also help evaluate the clinical significance of the result (Table IV). If the plasma concentration of the drug is within the therapeutic range, an adaptation of the dose is, of course, only recommended when clinical reasons, such as adverse effects or nonresponse, clearly justify such a decision. When the advice given on the TDM report is not followed, the reason for such a decision should be carefully documented.