Critically ill patients who receive high-level invasion show physiological changes different from those under more normal conditions, along with variable therapeutic effects and pharmacokinetics. The concept of systemic inflammatory response syndrome (SIRS) has been introduced to describe the clinical state resulting from invasive actions taken under acute circumstances, resulting in an acute-phase systemic response. In particular, dosages of vancomycin (VCM) and phenytoin (PHT) need to be adjusted by therapeutic drug monitoring (TDM) because of their narrow therapeutic concentration windows. However, there are few reports on the pharmacokinetics of VCM and PHT in patients with SIRS. We performed a retrospective cohort study of patients treated with VCM and PHT. These studies suggest that the pharmacokinetics of VCM are affected by SIRS score and duration. Furthermore, the concentration of PHT was also shown to be higher in SIRS patients compared with non-SIRS patients. These findings suggest that the pharmacokinetics of VCM and PHT may be affected by the pathology of SIRS, rather than by other patient characteristics. Modifying dosing according to SIRS will improve the prediction accuracy of drug concentration based on TDM. In this review, I introduce work conducted by pharmacists in the clinical study of critically ill patients, and will be discussing the evaluation of pharmacotherapy in emergency and intensive care medicine.
Keywords: invasion; phenytoin; systemic inflammatory response syndrome; vancomycin.