Basic Pharmacologic Concepts

Pharmacokinetic and pharmacodynamic principles specifically describe the different ways a drug and the body interact with each other. Pharmacokinetics focuses mainly on the absorption of medications into the body, the distribution into various tissues, how the body metabolizes and breaks down medications, and the elimination of any remaining medication or metabolites. Moreover, patient-specific characteristics, such as comorbidities and organ dysfunction, must be considered as they may also influence a drug’s absorption, distribution, metabolism, and elimination. Pharmacodynamics involves the different ways a medication affects the body, particularly when interacting with different receptors and the subsequent biochemical actions that elicit physiologic responses. Different drug-specific properties, such as affinity, efficacy, and agonism, also play a role in a patient’s response to the medication. When the concepts of pharmacokinetics and pharmacodynamics are joined together, computer models and simulations can be utilized to help predict the expected physiologic effects of a drug based on varying dosing parameters while taking tissue distribution and metabolism into consideration. This review contains 6 figures, 5 tables and 21 references. Keywords: biophase, compartment distribution, context-sensitive half-time, dose-response relationship, pharmacodynamics, pharmacokinetics, pharmacogenomics, receptor sensitization