Flashcards in Pharmacology 1, 2 and 3 - Intro to drug action, drug movement in the body, elimination Deck (93)
What are the 2 compromises of pharmacology and what do they mean?
Pharmacodynamics - what a drug does to the body (biological effects and mechanisms of action)Pharmacokinetics - what the body does to a drug (absorption, distribution, metabolism and excretion)
What selectively of drugs result from?
chemical structure of drugTarget recognising only ligands of a precise type
Examples of targets of drugs? (5)
enzymes, carrier molecule, ion channels, receptors, RNA/DNA
What are receptors?
Macromolecules that mediate the biological actions of hormones and neurotransmitters
2 types of drugs acting on receptors and meaning?
Agonists - a drug that binds to a receptor and produces a cell responseAntagonists - a drug that blocks the actions of agonists
What is a ligand?
A molecule that binds to a receptor
Out of affinity and efficacy, what does an agonist and antagonist posses?
Agonist = affinity and efficacyAntagonist = affinity
How does an agonist work?
A conformational change occurs due to the presence of an agonist molecule making it act and therefore producing a biological response
Strength of association between ligands and receptor
Dissociation rate compared to affinity
Low affinity = high dissociation rate
What are the 2 things that determine affinity
Closer the fitNumber of bonds
Ability of agonist to provoke a cellular response
Low ability to produce a cellular response
Relationship between receptor occupancy and agonist concentration?
As agonist conc. increases, receptor occupancy also increases
Concentration of agonist which elicits a half maximal response
Concentration (or dose) response relationship - linear plot - relationship shape
Why is it easier to plot the concentration response relationship as the log of the agonist concentration?
It allows you to present data over a wider range of concentrations It is easier to see the max70% of the curve is a straight line
What shape is the response when the concentration response relationship is plotted as a semi-logarithmic plot?
What can a highly potent drug do?
Evoke a larger response at lower concentrations
What are partial agonists
Drugs that bind to receptors but only have partial efficacy meaning they cannot evoke the same response as a full agonist
Binding of agonist and antagonist occur at same (orthosteric) site
Agonist binds to orthosteric site and antagonist binds to allosteric site (activation cannot occur if antagonist is bound)
The fate of drugs in the body
Determinants of drug disposition
The process by which a drug enters the body from its site of administration
The process by which the drug leaves the circulation and enters the tissues perfused by the blood (once inside the tissue, further blood-independant distribution may occur)
The process by which tissue enzymes (particularly in the liver-hepatic metabolism) catalyse the chemical conversion of a drug to a more polar form that is more readily excreted by the body
The process that removes the drug from the body (principally the kidneys - renal exertion)
Aside from the liver, where does metabolism also occur?
GI tract and lungs