What is the correct order of pharmacokinetics in the body?

The correct order of pharmacokinetics in the body is absorption, distribution, metabolism, and excretion. This sequence reflects the processes that a drug undergoes after administration.

Absorption is the first step, where the drug is taken into the bloodstream from the site of administration, such as the gastrointestinal tract or through a muscle. Following absorption, distribution occurs, where the drug is transported through the bloodstream to various tissues and organs in the body.

Once it reaches its target sites, metabolism begins. This process primarily occurs in the liver, where the drug is chemically altered into metabolites, which can either be active or inactive. Finally, excretion is the last step, in which the metabolites and any unchanged drug are eliminated from the body, mainly through the kidneys in urine or via biliary excretion in feces.

This order is crucial for understanding how drugs act within the body and is fundamental to pharmacology and clinical practice. Recognizing these stages allows healthcare providers to predict how different factors, such as age, disease, and concurrent medications, can affect a patient’s response to a therapeutic regimen.