Where does the majority of drug excretion take place?

The kidneys play a pivotal role in the excretion of drugs and their metabolites from the body. This process primarily occurs through filtration in the glomeruli and secretion in the renal tubules. The kidneys are specifically designed to remove waste products, including drug molecules, and help maintain balance in the body’s fluids and electrolytes.

Once drugs are metabolized, they often become more water-soluble, which facilitates their excretion through urine. The kidneys filter blood, remove excess substances, and ultimately excrete them, making it the most significant organ for drug elimination. While other organs like the liver, lungs, and skin may also excrete certain substances, the kidneys handle the majority of drug excretion, particularly for hydrophilic molecules.

Understanding this process is essential in veterinary pharmacology, as it helps practitioners anticipate how drugs will behave in an animal's body, informing dosing regimens and the potential for drug accumulation or toxicity due to impaired kidney function.