Excretion

Definition

Excretion is the process by which drugs and their metabolites are eliminated from the body, primarily through the kidneys in urine or through bile in feces. It is a crucial aspect of pharmacokinetics that influences drug duration and intensity.

5 Must Know Facts For Your Next Test

1. The primary organs involved in excretion are the kidneys and liver.
2. Renal excretion involves filtration, secretion, and reabsorption processes in the kidneys.
3. Factors such as age, renal function, and hydration status can affect drug excretion rates.
4. Drugs that are not lipid-soluble are typically excreted unchanged in urine.
5. The half-life of a drug is influenced by its rate of excretion.

Review Questions

• What are the primary organs responsible for drug excretion?
• How does renal function impact drug excretion?
• Why is understanding excretion important in determining a drug's dosage and frequency?

Related terms

Pharmacokinetics:

The study of how drugs move through the body, encompassing absorption, distribution, metabolism, and excretion.

Metabolism:

The chemical alteration of a drug by the body to facilitate its elimination.

Half-Life:

The time required for the concentration of a drug in the bloodstream to reduce by half.