What are the four phases of pharmacokinetics?

The four phases of pharmacokinetics are absorption, distribution, metabolism, and excretion, which accurately outlines the processes a drug undergoes within the body.

In the absorption phase, the drug enters the bloodstream from its site of administration, which can influence how quickly and effectively the drug takes effect. Next, distribution refers to how the drug is transported throughout the body and delivered to the target tissues or organs, influenced by factors such as blood flow and the drug's affinity for various tissues.

Metabolism, often occurring primarily in the liver, is the biochemical process where the drug is chemically altered, typically to facilitate excretion. This phase is crucial for determining the duration and intensity of the drug's action. Finally, excretion is the phase in which the metabolites or unchanged drug are eliminated from the body, primarily through the kidneys, lungs, or bile.

Understanding these phases is fundamental as it helps healthcare professionals predict how drugs will behave in the body, ensuring efficacy and safety in therapeutic applications.