drugmetabolisme

Drug metabolism refers to the biochemical modification of drug molecules by living organisms, primarily through the action of enzymes. This process is crucial for the body to eliminate foreign substances, including medications. The liver is the principal site of drug metabolism, although other organs like the kidneys, intestines, lungs, and skin can also contribute.

The primary goal of drug metabolism is to convert lipophilic (fat-soluble) drugs into more hydrophilic (water-soluble) compounds, making them easier to excrete from the body, typically via urine or bile. This transformation often occurs in two phases. Phase I metabolism involves introducing or exposing functional groups like hydroxyl (-OH), amino (-NH2), or carboxyl (-COOH) groups. This is commonly achieved through oxidation, reduction, or hydrolysis reactions, often catalyzed by the cytochrome P450 (CYP) enzyme superfamily.

Phase II metabolism, also known as conjugation, involves attaching an endogenous molecule (like glucuronic acid, sulfate, or glutathione) to the drug or its Phase I metabolite. This further increases the water solubility and facilitates excretion. While metabolism generally leads to inactivation of a drug, some drugs are actually activated through metabolism, a process known as a prodrug. Conversely, metabolism can sometimes produce toxic metabolites.

Factors such as genetics, age, disease states, diet, and the presence of other drugs can significantly influence the rate and pathways of drug metabolism, leading to variations in drug response and potential for drug interactions. Understanding drug metabolism is fundamental in pharmacology and medicine for optimizing drug therapy and predicting patient responses.