What process describes the removal of drugs or their metabolites through urine?

The process that describes the removal of drugs or their metabolites through urine is known as renal excretion. This process primarily occurs in the kidneys, where blood is filtered to remove waste products, including drugs and their breakdown products, which are then excreted in urine. Renal excretion is a key component of pharmacokinetics, as it influences the duration and intensity of a drug's action in the body.

Filtration, while a component of the renal excretion process, specifically refers to the initial filtering of blood in the glomerulus, which is just one step in the larger process of renal excretion. Biotransformation and metabolism refer to the chemical changes that drugs undergo in the body, transforming them into metabolites, but they do not specifically describe the removal of these substances.