Which of the following processes occurs primarily in the kidneys?

The process that occurs primarily in the kidneys is elimination. Elimination refers to the removal of drugs and their metabolites from the body, the kidneys play a crucial role in this by filtering blood to excrete waste products and excess substances through urine. This process involves glomerular filtration, tubular secretion, and tubular reabsorption.

Through these mechanisms, substances such as drugs can be either reabsorbed back into the bloodstream or excreted out of the body. This renal function is essential for maintaining the balance of fluids and electrolytes in the body and for clearing potentially harmful substances after they have been metabolized. The kidneys are the primary organs responsible for this elimination process, making it a key aspect of pharmacokinetics.

In contrast, absorption refers to the process by which drugs enter the bloodstream and occurs mainly in the gastrointestinal tract, distribution involves how drugs disperse throughout the body and into various tissues after entering the bloodstream, and metabolism primarily takes place in the liver, where drugs are chemically modified. Each of these processes is important in pharmacokinetics, but elimination is specifically linked to kidney function.