Drug Excretion and Elimination

Following metabolism, drugs are excreted from the body through various routes, predominantly via the kidneys, liver, or intestines. Renal excretion is a primary route for many drugs, with the kidneys filtering drugs from the blood into urine for elimination. Factors such as glomerular filtration rate and tubular secretion influence the rate of renal excretion and can impact drug concentrations in the body. Hepatic excretion involves drugs being transported into the bile for elimination through the feces, a process known as biliary excretion. In some cases, drugs may undergo enterohepatic recirculation, where they are reabsorbed in the intestines, affecting their elimination half-life. Understanding the mechanisms of drug excretion is essential for dose adjustments in patients with impaired renal or hepatic function and aids in minimizing drug accumulation and toxicity.