Cardiovascular System Pharmacology Case Study Background Pharmacokinetics and pharmacodynamics influence the drug’s effectiveness and availability in the body. Pharmacokinetics describes the drug's movement from entry to elimination points (Mathias, McAleer & Szollosi, 2020). On the other hand, pharmacodynamics entails the drug's action in the body cells (Hill, Kenakin, & Blackburn, 2017). The main pharmacokinetic phases are metabolism, bioavailability, absorption, and elimination. Metabolism begins once a person ingests a pharmacologic agent. Enzymes in the mouth, stomach, and liver break down drugs to metabolites to increase solubility (Currie, 2018). The movement of metabolites across the intestinal mucosal to the circulatory system is absorption (Hill et al., 2017). Once in the circulatory system, blood transports the metabolites to the target cells. McGavock (2017) describes bioavailability as the rate at which pharmacological molecules get into the bloodstream for transportation to the target sites. Once the metabolites achieve the intended therapeutic actions, they undergo fecal, skin, or renal system elimination from the body.