Pharmacology 1, 2 and 3 - Intro to drug action, drug movement in the body, elimination Flashcards Preview

1st Year - Principles > Pharmacology 1, 2 and 3 - Intro to drug action, drug movement in the body, elimination > Flashcards

Flashcards in Pharmacology 1, 2 and 3 - Intro to drug action, drug movement in the body, elimination Deck (93)
Loading flashcards...
1

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)

2

What selectively of drugs result from?

chemical structure of drugTarget recognising only ligands of a precise type

3

Examples of targets of drugs? (5)

enzymes, carrier molecule, ion channels, receptors, RNA/DNA

4

What are receptors?

Macromolecules that mediate the biological actions of hormones and neurotransmitters

5

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

6

What is a ligand?

A molecule that binds to a receptor

7

Out of affinity and efficacy, what does an agonist and antagonist posses?

Agonist = affinity and efficacyAntagonist = affinity

8

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

9

Affinity?

Strength of association between ligands and receptor

10

Dissociation rate compared to affinity

Low affinity = high dissociation rate

11

What are the 2 things that determine affinity

Closer the fitNumber of bonds

12

Efficacy?

Ability of agonist to provoke a cellular response

13

Low efficacy?

Low ability to produce a cellular response

14

Relationship between receptor occupancy and agonist concentration?

As agonist conc. increases, receptor occupancy also increases

15

EC50?

Concentration of agonist which elicits a half maximal response

16

Concentration (or dose) response relationship - linear plot - relationship shape

Hyperbolic

17

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

18

What shape is the response when the concentration response relationship is plotted as a semi-logarithmic plot?

Sigmoidal

19

What can a highly potent drug do?

Evoke a larger response at lower concentrations

20

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

21

Competitive antagonism?

Binding of agonist and antagonist occur at same (orthosteric) site

22

Non-competitive antagonism

Agonist binds to orthosteric site and antagonist binds to allosteric site (activation cannot occur if antagonist is bound)

23

Drug disposition?

The fate of drugs in the body

24

Determinants of drug disposition

AdsorptionDistributionMetabolismExcretion

25

Adsorption?

The process by which a drug enters the body from its site of administration

26

Distribution

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)

27

Metabolism

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

28

Excretion

The process that removes the drug from the body (principally the kidneys - renal exertion)

29

Aside from the liver, where does metabolism also occur?

GI tract and lungs

30

Aside from the kidneys, where does excretion also occur?

Breath, sweat and milk