Intro to Pharmacokinetics Flashcards
What is pharmacokinetics?
The process that determines the concentration of drug in the blood plasma including how it is metabolised
What is pharmacodynamics?
The effect of the drug in the body, how it interacts and what effects it produces
What are plasma concentrations important for?
Delivery of molecules to tissues
Removal of molecules from tissues
What are “hit and run” drugs?
Drugs that continue to produce an effect even after they have been removed from the body e.g anitbiotics
What does ADME stand for?
Administration, distribution, metabolism, excretion
Which 2 organs are involved in removing drugs from the body?
Liver: metabolism
Kidneys: filtration into the urine
Which type of drugs undergo most metabolism?
Lipid-soluble since they need to be made more soluble to make them more water soluble
What is the difference between enteral and parenteral drugs?
Enteral = Enters the GI tract Parenteral = bypasses the GI tract
What is bioavailability?
The proportion of an administered drug that reaches the systemic circulation
Which drug route has a bioavailability of 100%?
IV
What is the main factor that affects bioavailability?
The extent to which the drug is absorbed in the GI tract
Why doesn’t the plasma concentration stay constant after administration?
Metabolism and excretion are constantly happening
What is TDM?
Therapeutic drug monitoring e.g taking samples of the plasma
What is the difference between free and total concentration of a drug?
Free = the molecules that are isolated and not bound to anything Total = Free concentration + bound concentration
What is the minimum effective concentration?
The smallest maintained total plasma concentration that will sustain the desired response
The concentration that must be exceeded at regular intervals (for “hit and run” drugs)
