Adrenergic Drugs

Question 1

Rate limiting step in adrenaline production

Answer 1

Tyrosine Hydroxylase

Question 2

Exceptions to sympathetic preganglionic and postganglionic neurotransmitters

Answer 2

Eccrine sweat gland = ACh to ACh

Renal vessels = ACh to Dopamine

Question 3

Different types of adrenoreceptors and function

Answer 3

A1,A2 = causes vasoconstriction to visceral organs and shutting down of GI tract
B1,B2,B3 = Causes vasodilation to skeletal muscles, increase in cardiac contractility and increase in heart rate

Question 4

Adrenoreceptors in eyes

Answer 4

A1 = pupil dilation by contraction of iris
A2 = reduce blood flow to cilliary body and reduce aqueous humour production, decrease PG production thus decreasing aqueous humour production
B1 = causes production of aqueous humour

Question 5

Adrenoreceptors in salivary glands

Answer 5

Alpha 2 adrenoreceptors in salivary glands inhibit saliva production

Question 6

Adrenoreceptors in lungs

Answer 6

Contain B2 adrenoreceptors causing bronchodilation

Question 7

Adrenoreceptors in CVS

Answer 7

Beta 1 = causes increase in heart rate and contractility
Beta 2 = vasodilation of blood vessel to skeletal muscle
Alpha 1 and 2 = causes vasoconstriction to visceral organs

Question 8

Adrenoreceptors in metabolism

Answer 8

Beta 3 causes lipolysis, thermogenesis. Beta 2 causes insulin secretion

Question 9

Adrenoreceptors in GIT

Answer 9

Alpha 1, Alpha 2 and Beta 2 decrease gastric motility and secretion
Alpha 1 causes Sphincter contraction

Question 10

Adrenoreceptors in bladder

Answer 10

Alpha 1 causes micturation

Beta 3 causes bladder relaxation

Question 11

Adrenoreceptors in reproductive system

Answer 11

Alpha 1 causes contraction of seminal vesicles and uterus

Beta 2 causes relaxation of uterus

Question 12

What is atropine

Answer 12

Atropine is a muscuranic agonist

Question 13

Direct adrenergic agonists are

Answer 13

Noradrenaline, adrenaline, dopamine, Oxymetazoline, Phenylephirine, Brimonidine, Isoprenaline, Dobutamine, Salbutamol/terbutaline, mirabegron

Question 14

Dopamine action on adrenoreceptors

Answer 14

Alpha 1 and Beta 1 direct agonist

Question 15

Oxymetazoline action on adrenoreceptors

Answer 15

Non-selective alpha adrenoreceptors agonist

Question 16

Phenylephirine actions

Answer 16

Alpha 1 specific direct agonist

Question 17

Brimonidine function

Answer 17

Alpha 2 specific agonist

Question 18

Isoprenaline function

Answer 18

Non-selective beta agonist

Question 19

Dobutamine function

Answer 19

Non-selective Beta 1 agonist

Question 20

Salbutamol/terbutaline function

Answer 20

Beta 2 agonist

Question 21

Mirabegron

Answer 21

Beta 3 agonist

Question 22

Enzymes that break down catacholamines

Answer 22

Monoamine oxidase (MAO)
Catachol - O - Methyltransferase (COMT)

Question 23

Moclobemide function

Answer 23

Indirect Non selective adrenoreceptor agonist
Works by suppressing function of MAO
Used as antidepressants

Question 24

Tricyclics antidepressants function

Answer 24

Works by inhibiting presynaptic uptake transporter 1

Increases NA conc. More than adrenaline

Question 25

Ephedrine and pseudoephidrine function

Answer 25

Taken up by presynaptic neurone uptake transporter 1 and competes for vesicular compartment with NA

It acts as competitive substrate for MAO

Ephedrine is also a potent alpha and beta adrenoreceptor agonist

Question 26

Why is beta blockers not used in patients with diabetes

Answer 26

Signs of hypoglycaemia is masked