Practical Pharmacokinetics and Pharmacodynamics

  • Anthony T. GerlachEmail author
  • Lina Saliba


The physiological responses to surgery, critical illness, and subsequent resuscitation can alter both pharmacokinetics (PK) and pharmacodynamics (PD) [1]. As a result of these changes, pharmacotherapy may need to be altered to produce the desired outcomes. A basic understanding of the principles of pharmacokinetics, or the movement of drugs in the body, and pharmacodynamics, the cells responses to drugs, is needed to maximize pharmacotherapy [2]. This chapter will review basic pharmacokinetic and pharmacodynamic principles and some changes in the critically ill surgical patient.


Drug dosing Drug metabolism Pharmacodynamics Pharmacokinetics Neuromuscular blockade Opiates Sedatives Drug monitoring 



Distribution half-life


Area under the curve


Terminal half-life




Maximum concentration


Steady-state maximum concentration


Steady-state concentration


Cytochrome P450




Free concentration time above minimum inhibitory concentration


Intensive care unit


Elimination constant


Loading dose


Length of stay


Minimum inhibitory concentration






Pharmacokinetics and pharmacodynamics


Therapeutic drug monitoring




Time above mean inhibitory concentration


Volume of distribution


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Authors and Affiliations

  1. 1.Department of PharmacyThe Ohio State University Wexner Medical CenterColumbusUSA
  2. 2.Department of PharmacyYale-New Haven HospitalNew HavenUSA

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