ABSTRACT
The optimization of drug doses in acutely ill patients is a difficult and multifactorial process.
The correct dose is one that exerts a desired therapeutic effect while producing minimal unde-
sirable side effects. Critically ill patients may experience physiologic and pharmacokinetic
changes that affect the disposition of medications (e.g., heart failure, renal failure, hepatic
failure, trauma, sepsis, and burns). To optimize doses, the critical care practitioner first
must evaluate these possible physiologic conditions for their effects on the absorption, distri-
bution, metabolism, and excretion of drugs. Other crucial factors to consider include both the
condition being treated and other disease states; drug interactions, tolerance, and penetration
to the site of action; other drug therapies; the therapeutic index of the drug; toxic effects; and
dose-response relationships. These factors are discussed in this chapter in a general way, and
a more specific examination is provided for cardiotonic drugs and agents for treating hyper-
tension, since use of these classes of drugs is prevalent in the SICU setting.
