Pharmacokinetics is a scientific word that describes how your body responds to a medicine. It helps us figure out how a medicine moves around in your body, how your body uses it, and when it leaves your body.
When you take a medicine, it goes into your body and travels around to different parts. Your body then starts to break the medicine down, so it can use it to help you feel better. As it moves around, some of the medicine is used up, and some of it is sent out of your body through your urine or your sweat. This process of the medicine moving around, being used up and sent out of your body is what pharmacokinetics is all about.