Pharamacokinetics Flashcards
What does pareteral mean?
the administration of drugs by any route other than the mouth
Purpose of the small intestines in relation to drugs
Major site for absorption of orally administered drugs
What is the hepatic first pass effect
Orally administered. drugs pass from the intestines to. the liver before reaching the systematic circulation resulting in a proportion of the medication being metabolised by the liver before it reaches the bloodstream
Define metabolism
The enzymatic breakdown of. a drug to a metabolite, that is typically less biologically active and more water soluble (easier to excrete in urine)
What is an agonist
A drug that binds to and activates the receptor., producing the same response as the endogenous ligand
What is an antagonist
A drug that binds to the receptors and blocks the access to the endogenous liana, thus diminishing the normal response
Adverse drug reaction Type A
Predictable, intended and desirable response to a drug
Adverse drug reaction Type B
Unpredictable, unintended, undesirable. response to a drug
What is lysis?
the breakdown of a cell caused by damage to its plasma (outer) membrane
Define pro-drug
A drug that is converted to its active form after absorption
Define pharmacogenetics
The study of genetic differences that can alter an individual response to a drug
Define pharmacodynamics
The study of the interaction. between a drug and its molecular target and the physiological response (MOA)
Define enzyme induction
Increase synthesis of more enzyme protein, leading to an increase in drug metabolism
What does specificity refer to
Refers to the narrowness of a drug; the property of the drug that acts at one site, producing one effect
What is a therapeutic index
A ratio that compares the blood concentration at which a drug becomes toxic and the concentration at which the drug is effective the larger the ratio the safer the drug is
What is zero order kinetics
elimination of drugs at a constant rate regardless of the plasma concentration
What is a loading dose
A larger than normal dose administrated as the first in a series of doses.
It is administered to achieve the therapeutic amount in the body more rapidly than would occur only by accumulation of the repeated in smaller doses
What is a receptor
A large group of proteins that are molecule targets for drugs and lipids
What is an enzyme
Biological molecule that catalyses a chemical reaction or causes a chemical change in another substance
Define steady state
The situation in which the rate of a drug administered equals the rate of elimination and the plasma concentration remains constant
Define half-life
The time taken for the blood or plasma concentration of a drug to fall by 50%
What does efficacy mean?
The ability of the drug achieved its desired therapeutic response
What isa ligand?
A substance that forma a complex with a receptor to serve a biological purpose
What does pharmacokinetics mean?
The study of how a drug is altered during the process of absorption, distribution, metabolises and excretion
Identify variables that may affect pharmacokinetics (all four phases)
Absorption - how the drug moves from the site of administration to site of action
Distribution - journey of the drug
Metabolism - process that breaks down the drug
Excretion - removal of drug from body
Explain why the vast majority of medications prescribed for paediatric and adolescent patients are based on weight
This is related to the varied pharmacokinetics, pharmacodynamics and disease process differences. Differences seen in the pharmacokinetics between adults and children and be related to a number of factors such as age, gender, body compositions, motivation of liver and kidneys and other systems
