How does the body metabolize drugs?

The body metabolizes drugs primarily through enzymatic processes that occur mainly in the liver. The liver contains a range of enzymes, particularly cytochrome P450 enzymes, which are crucial for the biotransformation of various substances, including medications. This metabolic process alters the chemical structure of drugs, which can lead to their activation, deactivation, or conversion into more water-soluble forms that can be easily excreted by the kidneys.

Metabolism involves several phases, including phase I reactions (which generally involve oxidation, reduction, or hydrolysis) and phase II reactions (which involve conjugation), effectively modifying the drugs for elimination from the body. The metabolic processes can be influenced by various factors such as age, genetics, liver function, and the presence of other medications, which may lead to variations in how individuals respond to drugs.

Other systems or methods mentioned, such as muscle contractions, the digestive system, or the respiratory system, do not play primary roles in drug metabolism. While the digestive system is involved in the absorption of drugs, it is not where significant metabolic conversion occurs. Similarly, muscle contractions and the respiratory system do not directly contribute to the enzymatic breakdown of drugs in the way that liver enzymes do.