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Flashcards in Pharmacology Deck (64)
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1

Define partial agonist

A drug that  fails to produce maximal effects even when all receptors are bound by the drug

2

Define potency

Potency is the amount of drug required to produce 50% of the maximal response the drug is capable of inducing

3

Define pharmacokinetics

What the body does to the drug

4

What type of receptor is the nicotinic cholinergic receptor?

Ligand-gated ion channel

 

5

Define efficacy

• Efficacy is the probability of a drug activating a receptor once bound
• Aka the degree to which a drug is able to produce maximal effects

6

Define pharmacodynamics

What the drug does to the body

7

Define affinity and how it is measured

• Affinity is the probability or strength of a drug binding to its receptors
• Measured with equilibrium dissociation constant

KA =  drug concentration required for 50% occupancy of receptors

8

Describe the journey a PO medication must take to reach systemic circulation

 GIT -> liver -> R) heart -> lung -> L) heart -> systemic circulation

9

Define each of ADME 

Absorption - how drug gets into circulation
Distribution - how drug spreads through body
Metabolism - chemical changes to the drug
Excretion - physical expulsion of the drug

10

What are the 6 steps in pharmacokinetics?

Administration, absorption, distribution, elimination, metabolism, excretion

11

Describe the 3 steps in ACh synthesis

1 Choline taken up into cell by choline carrier

2 Choline + acetyl-CoA → acetylcholine + CoA via choline acetyltransferase

3 ACh put into vesicle

12

What is a clinical use for nicotinic receptor antagonists?

Pre-surgical muscle relaxant

13

Name 3 clinical uses of ACh esterase inhibitors

 

Dx of myasthenia gravis

Rx of myasthenia gravis

Rx of Alzheimer's disease

 

14

What is a clinical use for nicotinic receptor agonists?

Smoking cessation

15

What is the mechanism of action of atropine?
What are 4 clinical uses of atropine?

 

 

Muscarinic antagonist.

Bronchodilation and decrease respiratory mucous in anaesthesia

To increase heart rate.

Pupil dilation for eye examination.

AChE-inhibitor poisoning (organophosphates)

 

16

What is the mechanism of action of botulimin toxin

Name 3 conditions it may be used for

Botulimin toxin inhibits presynaptic ACh release by inhibiting vesicular exocytosis by acting as a protease on SNARE proteins.

Used to treat dystonia, migraine or underarm sweating

17

What are H2 antagonists used to treat and what is their mechanism of action?

Used to treat peptic ulcers.

Inhibit acid secretion by parietal cells in stomach by disrupting proton pump.

 

18

H1 antagonists:

What class of drugs are these?

Name 5 things they are used to treat.

Name 2 new generation drugs

 

Antihistamines

Used to treat hayfever, itchiness, motion sickness, anaphylaxis, bites/stings
New generation = cetirizine, loratidine

 

19

Describe the 4 steps in NA synthesis

1 Tyrosine taken up into cell
2 Tyrosine → L-Dopa (catalysed by tyrosin hydroxylase)
3 L-DOPA → Dopamine (catalysed by dopa decarboxylase)
4 Dopamine taken up into vesicle and converted into NA (catalysed by dopamine beta hydroxylase)

20

What are 7 clinical consequences of adrenaline administration?

Vasoconstriction

GI muscle relaxation

Salivation

Hepatic glycogenolysis

Increased heart rate

Increased cardiac contractility

Bronchodilation

21

What is the mode of action of aminoglycosides?

Aminoglycosides bind to specific proteins in 30s ribosome subunit and inhibit binding of formylmethionyl-tRNA (fmet-tRNA) to ribosome, thus inhibit protein synthesis,

Also cause misreading of mRNA codons

22

How do beta lactams exert antimicrobial effects?

Beta lactams inhibit synthesis of cell wall by binding to PBPs (penicillin-binding proteins)

23

List 3 enzymes that beta lactams may inhibit

Transpeptidase
Transglycosylase
Carboxypeptidase

24

What is the mechanism of action of loop diuretics?

Inhibit Na/K/2Cl carrier in ascending loop of Henle

25

What is the mechanism of action of potassium-sparing diuretics?

Block Na transporter in collecting tubules and ducts

Plus or minus:

Inhibit synthesis of Na/K cotransporter in collecting tubules and ducts

26

What is the mechanism of action of thiazide diuretics?

Inhibit Na/Cl transporter in distal tubule

27

What are 7 clinical consequences of adrenaline administration?

Vasoconstriction

GI muscle relaxation

Salivation

Hepatic glycogenolysis

Increased heart rate

Increased cardiac contractility

Bronchodilation

28

How does penicillin exert its antimicrobial effect?

 Penicillin stops formation of pentapeptide bridge by blocking transpeptidase

29

List 3 enzymes that beta lactams may inhibit

Transpeptidase
Transglycosylase
Carboxypeptidase

30

What are 6 clinical effects of muscarinic antagonists (aka anticholinergics)?

Dry eyes

Dry mouth

Urinary retention

Constipation

Tachycardia

Confusion