How are most drugs eliminated from the body?

Most drugs are eliminated from the body primarily through two processes: metabolism and excretion. Metabolism involves the chemical alteration of the drug by the body's enzymes, typically in the liver, which transforms the drug into more water-soluble compounds. This transformation is crucial because it prepares the drug for excretion by the kidneys.

Once a drug is metabolized, the resulting metabolites can then be excreted from the body, mainly through the kidneys into urine, but also through bile into feces and, to a lesser extent, through sweat, saliva, and exhaled air. This dual process is vital as it ensures that the drugs are effectively removed from the circulating system, thereby preventing potential toxicity or prolonged effects.

Focusing on the other choices, relying solely on excretion (the first option) or solely on metabolism (the second option) does not accurately represent how drug elimination works in practice. Drug elimination is rarely achieved through just one of these processes. Similarly, elimination through filtration alone (the fourth option) does not encompass the complete processes of metabolism and excretion, as filtration is just one mechanism of renal function and does not account for metabolic transformations. Thus, the option that includes both metabolism and excretion reflects the comprehensive approach to drug elimination in