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Flashcards in Pharmacology Deck (52):
1

What is Pharmacodynamics

What a drug does to the BODY

2

What is Pharmacokinetics

What your BODY does to a DRUG

3

What is an agonist?

Drug that binds to a receptor to produce a cellular response.
E.g - Adrenaline to B1 receptors in the heart

4

What is affinity?

The strength of association between ligand and receptor

5

What is efficacy?

The ability of an agonist to produce a response

6

What is an antagonist?

Drug that blocks the binding of an agonist

7

True/ False.
An antagonist possess affinity and efficacy

False
Possess affinity but NOT efficacy

8

A competitive antagonist binds to the same/different site as an agonist

Same

9

A non-competitive antagonist binds to the ______ site

Allosteric

10

Ligand Gated Ion Channels are made of ________ subunits

Glycoprotein

11

Ligand Gated Ion Channels allow for rapid/slow movement of ions

Rapid

12

How many times does a G Protein Coupled Receptor span a membrane?

7

13

How many polypeptide subunits is a G protein made up of?

3

14

Describe the mechanism of action of G-protein

Receptor binds to GPCR, G-protein couples with receptor and GDP dissociates to form GTP, G protein dissociated into alpha and By subunits and alpha subunit combines with effector producing a cellular response

15

Gs alpha subunit activates/deactivates adenylyl cyclase to activate the cAMP pathway

Activates

16

cAMP activates _____

Protein Kinase A

17

What are the 4 fates of drugs in the body

Absorption
Distribution
Metabolism
Excretion

18

Absorption is ....

Process by which a drug enters the body

19

Distribution is ....

Transfer of drug from systemic circulation to tissues

20

Metabolism is ....

Polarisation of drugs (mainly by liver) to be prepared for excretion

21

Excretion

Removal of drugs from the body

22

Name the 4 factors affecting drug absorption

Solubility
Chemical Stability
Lipid to water partition coefficient
Degree of ionisation

23

Solubility is .....

How well a drug dissolves

24

Chemical Stability is ....

Structural integrity of the drug (may be destroyed by stomach acid)

25

Lipid to water partition coefficient is ....

Rate of diffusion of the drug increases with the rate of solubility
i.e more soluble = more diffusion

26

Degree of ionisation refers to ....

The fact that only unionised drugs can pass the lipid bilayer

27

pKa is ....

pH at which 50% of the drug is ionised and 50% is unionised

28

Oral availability is ....

the fraction of drug that reaches the systemic circulation after oral ingestion

29

Enteral routes of administration

Oral
Sublingual (under tongue)
Rectal (up the pooper shooter)

30

Parenteral routes of administration (6)

Intravenously (IV)
Intramuscular (IM)
Subcutaneous (SC)
Inhalation (Inh)
Transdermal
Topical

31

True/ False
Drugs are evenly distributed over the body?

False

32

What is the volume of distribution (Vd)

Volume at which a drug is dissolved (Vd)

33

What is MEC

Minimum Effective Concentration -
Minimum concentration for a drug to be effective

34

What is MTC

Maximum Toxic Concentration -
Maximum concentrado before unwanted side effects

35

How would you calculate the therapeutic ratio

MTC/MEC

36

What drug has a narrow therapeutic ratio

Cardiac glycosides e.g Digoxin

37

Describe first order kinetics

Rate of elimination is directly proportional to the drug concentration

38

True/ false
If clearance is high then not much of the drug is lost in the urine

False
If rate of elimination is high then a lot of the drug is lost in the urine

39

Rate of elimination = Clearance X ______ _____

Plasma volume

40

Steady state means

Drug absorbed = rate of elimination

41

Steady state of concentration is usually achieved after _ half lives

5

42

At what rate are drugs eliminated at in ZERO order kinetics

Constant rate (drug elimination not proportional to concentration)

43

What does drug metabolism do?

Makes drugs polar (less active)

44

Where does most drug metabolism occur?

The liver

45

What happens in phase 2 of drug metabolism by the liver?

Conjugation (increasing polarity) and addition of an endogenous compound

46

Drugs that pass first pass metabolism are excreted quicker/slower than the parent compound

Quicker

47

How are most drugs filtered

Glomerular filtration

48

True/ false
Drugs bound to proteins cannot easily be filtered by glomerular filtration

True

49

What are the two systems of active tubular secretion?

Organic anion transporter (acids)
Organic cation transporter (bases)

50

What can active tubular secretion do that glomerular filtration cannot?

Secrete drugs that are protein bound

51

What percentage of water filtered by glomerular filtration is reabsorbed?

99%

52

Name the 4 factors that facilitate reabsorption

Lipid solubility (more soluble more reabsorption)
Polarity (more polar less secretion)
Urinary flow rate (more pee more secretion less reabsorption)
Urinary pH (alkaline-secretion of acid, acid-secretion of bases)