What Happens to Medicine in Your Body?

Medicines administered orally, by inhaler, and intravenously enter the stomach, lungs, and veins, respectively. They’re absorbed, then circulate throughout the body in the blood, are processed by the liver, and excreted by the kidneys and intestines. Credit: NIGMS. Have you ever wondered what happens inside your body when you take a medicine? An area of pharmacology called pharmacokinetics is the study of precisely that. Here, we follow a medicine as it enters the body, finds its therapeutic target (also called the active site), and then eventually leaves the body. To begin, a person takes or is given a dose of medicine by a particular route of administration, such as by mouth (oral); through the skin (topical), mucous membranes(nasal), or lungs (inhaled); or through a needle into a muscle (intramuscular) or into a vein (intravenous). Sometimes medicines can be administered right where they’re needed, like a topical antibiotic ointment on a scrape, but most medicines need to enter the blood to reach their therapeutic target and be effective. Those are the ones we’ll continue following, using the common pharmacokinetic acronym ADME: Absorption: The body absorbs the medicine from its administration point into the blood stream. The amount absorbed varies depending on the route of administration and the medicine’s molecular properties. Pharmacologists determine the bioavailability of a medicine, or the percentage of the administered dose that gets into t...
Source: Biomedical Beat Blog - National Institute of General Medical Sciences - Category: Research Authors: Tags: Being a Scientist Chemistry, Biochemistry and Pharmacology Common questions Medicines Miniseries Source Type: blogs