LCRS Pharm quiz

Question 1

Which of the following forms of drug antagonism describes the ability of adrenaline to reduce the effects of mast cell derived histamine during an anaphylactic response.

a) Receptor blockade
b) Physiological antagonism
c) Chemical antagonism
d) Pharmacokinetic
d) antagonism
e) Irreversible antagonism

Answer 1

ans = b) Physiological antagonism

Question 2

Thirty minutes after administration, blood levels of a drug are higher in the hepatic portal venous system than in the major arteries (systemic blood levels). Which route of administration was utilised for this drug?

a) Inhalational
b) Intravenous
c) Oral
d) Sublingual
e) Transdermal

Answer 2

c) Oral

Question 3

How do muscarinic receptor antagonists influence function
within the striatum and thus improve the symptoms of
Parkinson’s?

a) Reduced GABA receptor activation
b) Increased dopamine receptor activation
c) Inhibition of DOPA decarboxylase
d) Increased monoamine reuptake transporter function
e) Increased dopamine secretion from nigrostriatal neurones

Answer 3

b) Increased dopamine receptor activation
- parkinsons = due to loss of dopaminergic neurones

• normally:
  musc receptors –> they inhibit the D1 receptors
• if you block the muscarinic receptor –> you increase the dopamine receptor sensitivity/ activation

Question 4

Which one of the following effects can be attributed to anti-cholinesterase poisoning?

a) Bronchodilation
b) Reduced gut motility
c) Increased secretions
d) Tachycardia
e) Mydriasis

Answer 4

c) Increased secretions

anti cholinesterase - less break down of Ach
–> look at which ones are effects of the parasympathetic NS

Question 5

A 54-year-old man is admitted to Accident & Emergency suffering an anaphylactic reaction after being stung by a wasp whilst out rambling. The registrar finds a bottle of beta-blocker tablets in his pocket. Which of the following clinical features of anaphylaxis could be worsened by these tablets?

a) Bronchospasm & Hypertension
b) Bronchospasm alone
c) Hypertension alone
d) Bronchospasm & Hyperglycaemia
e) Hypertension & Hyperglycaemia

Answer 5

b) Bronchospasm alone
- analphylaxis causes hypotension + bronchospasm

- action of beta blockers --> 
cause bronchoconstriction 
decrease HR 
impairs glycemic control  
but usually only bronchospasm is associated.

Question 6

Which of the following neurones is associated with noradrenaline neurosecretion?

a) Preganglionic sympathetic neurone innervating the sympathetic trunk
b) Postganglionic sympathetic neurone innervating the kidney
c) Sympathetic neurone innervating the adrenal medulla
d) Postganglionic parasymapthetic neurone innervating the heart
e) Postganglionic sympathetic neurone innervating the sweat gland

Answer 6

ans = b

b) Postganglionic sympathetic neurone innervating the kidney

not C

• because the adrenal medulla is what releases the NA/A
• but it in itself receives Ach neurotransmitters
• all preganglionic = Ach

Question 7

A 75-year-old man is diagnosed with glaucoma and is treated with a α1 selective adrenoceptor agonist. The therapeutic effects of the drug are partly due to which of the following functions?

a) Dilation of the pupil
b) Activation of carbonic anhydrase
c) Accomodation for near vision
d) Opening of scleral venous drainage
e) Vasoconstriction of ciliary body arterioles

Answer 7

e) Vasoconstriction of ciliary body arterioles
- a1 adrenoreceptor agonist = causes vasoconstriction of ciliary body
- a2 adrenoreceptor agonist = causes contraction of sphincter pupillae, which increases venous drainage
- B2 adrenoreceptor agonist = activates carbonic anhydrase

Question 8

The figure below shows the response associated with a 10mg/kg dose of drug A (represents the ED50 for drug A). If you repeated this dose of drug A in the presence of a fixed dose of the relevant competitive receptor antagonist, where would you expect the “x” to be placed on the graph above in comparison to its current position?

A. Directly above
B. Directly below
C. Shifted to the left
D Shifted to the right
E Superimposed

Answer 8

ANS = B

• for a single specific dose, as the whole graph shift towards the right, the agonist has less of an effect due to the competitive antagonists

at a particular dose –> there is less response to an agonist –> so it is directly below (the original point)