Patient: Alpha Adrenoceptors Flashcards Preview

Pharmacy Year 2 Semester 1 > Patient: Alpha Adrenoceptors > Flashcards

Flashcards in Patient: Alpha Adrenoceptors Deck (42):
1

Two branches of the autonomic nervous system and what kind of receptors lie there

Sympathetic- noradrenaline
Parasympathetic - acetylcholine

2

Adrenal Medulla

Adrenaline (epinephrine)
which is under he sympathetic nervous system

3

Adenoreceptors modulate the "fight or flight" response. Name 9 examples of tissues where they can act

-Blood vessels
-heart
-Lungs
-GI tract
-Salivary glands
-bladder
-genitalia
-eyes
-sweat glands

4

Name 3 adrenoreceptors

Alpha1, alpha2
beta1, beta2, beta3

5

Functional responses of alpha1 adrenoceptors

-GPCR - Galphaq
-Increases Ca2+ concentration via..activating phospholipase C-->IP3
-vasoconstriction (increase BP)
-Contraction of visceral smooth muscle e.g. bladder sphincter, uterus, iris radial muscle, seminal tract, pilomotor muscles
-Relax GI tract

6

Define seminal tract

Secrete semen

7

Define pilomotor muscles

Contraction of the smooth muscle of the skin caused by mild application of a tactile stimulus or by local cooling and resulting in goose bumps

8

Functional response of alpha2 adrenoceptors

-Decrease in noradrenaline and acetylcholine transmitter release
-Decrease in insulin release
-GPCR Galphai activates adenylyl cyclase
-causes reduction in cAMP
-Decrease in Protein kinase A

9

Functional response of beta1 adrenoceptors in the
Heart
Kidney
Adipocytes

Binds GPCR Galphas
activates adenylyl cyclase
increase in cAMP
increase in protein kinase A hence:
Heart - Increase heart rate (SA node) and increase force of contraction
Kidney - release of renin
Adipocytes - activates lipolysis

10

Describe what renin is

Hormone that affects:
-Na reabsorption
-angiotensin 2
-vasoconstrictor

11

Functional response of beta2 adrenoceptors

GPCR
Galpha2s
activates adenylyl cyclase
increase in cAMP
increase PKA

Bronchodilation-vasodilation (sk muscle) very little change in BP
-relax visceral smooth muscle
-bladder
-detrusor muscle
-uterus
-ciliary muscle
-seminal tact
-muscle tremor
-glcogenolysis

12

Define detrusor muscle

Muscle that forms layer of wall in the bladder

13

Define ciliary muscle

muscle in the eye
forms part of the ciliary body

14

Name an alpha1 agonist

Phenylephrine

15

Name an alpha2 agonist

Clonidine

16

Name a beta1 agonist

Dobutamine

17

Name a beta2 agonist

Salbutamol

18

Name an agonist that works on both alpha1 and alpha2 receptors

Methoxamine

19

Name an agonist that works on both beta1 and beta2 receptors

Isoprenaline

20

Name an agnoist compound that work on alpha1, alpha2 and beta1 adrenoreceptors

Noradrenaline

21

Name an agnoist that works on alpha1, alpha2, beta1, beta2 receptors (all 4)

Adrenaline

22

Name an alpha1 antagonist for adrenoreceptors

Prazosin

23

Name an alpha2 antagonist for adrenoceptors

Yohimbine (not in clinical use)

24

Name a beta1 antagonist for adrenoceptors

atenolol

25

Name a beta2 antagonist for adrenoceptors

Butoxamine

26

Name two antagonists that work on both alpha1 and alpha2 adrenoceptors

Phentolamine (competitive)
Phenoxybenzamine (non-competitive)

27

Name an antagonist that works on both beta1 and beta2 adrenoceptors

Propanolol

28

Structural difference between noradrenaline and adrenaline

Same but Adrenaline has a CH3 off the amine group
whereas noradrenaline just has a H atom off it

29

How is adrenaline for cardiopulmonary resuscitation

As an adjunct to cardiopulmonary resuscitation
By causing arterial and venous vasoconstriction, adrenaline increases the blood pressure
Blood flow in coronary and cerebral arteries is promoted
In ventricular fibrillation, adrenaline may coarsen the ECG waveform, and render electrical cardio-version more likely to suceed

30

Name 2 clinical uses of adrenaline

-adjunct to cardiopulmonary resuscitation
-to control anaphylactic shock

31

Name symptoms of anaphylactic shock

-Profound hypotension
-Largngeal Oedema
-Bronchospasm

32

2 main ways to control anaphylactic shock and how to address it therapeutically

1.Restore blood pressure
-Patient with feet raised (supine)
-Adrenaline IV (slowly) or IM every 10 minutes
alpha1 adrenoceptor activated, vasoconstriction occurs and causes an increase in blood pressure
2. Secure the airway/administer oxygen
-Beta2-adrenoceptor
-bronchodilation
-decrease histamine release

33

Name 2 drugs you would use to control a case of anaphylactic shock

Chlorpheniramine (Slow IV injection)
Hydrocortisone IV

34

How are agonists used to reduce intra-ocular pressure in chronic simple glaucoma?

Adrenaline eyedrops used
They reduce the production of aqueous humor and increase its drainage through the trabecular meshwork

35

How are agonists used alongside local anaesthetics?

Local anaesthetics cause vasodilation and hence facilitate their own redistribution
Addition of adrenaline to local anaesthetic causes vasoconstriction (mediated by alpha-adrenoceptors) and prolongs the action of the local anaesthetic and reduces its systemic toxicity

36

When do you avoid use of vasoconstrictors?

Near bases of body appendages and digits

37

What is Phenylephrine used for?

alpha1-selective agonist at adrenoceptors
it is used to offset the hypotension attributable to sympathetic block induced by spinal or epidural anaesthesia
ALSO:
To produce brief periods of mydriasis (pupil dilation) using eyedrops

38

Where is phenylephrine injected for:
1-Spinal anaesthesia
2-epidural anaesthesia

1-injected into subarachnoid space
2-epidural space

39

What is a Phaeochromocytoma? How is it treated?

Tumour of the adrenal medulla that secretes adrenaline erratically, causing episodes of severe hypertension
treated with antagnoists of adrenoceptors: Phentolamine for treatment
and Phenoxybenzmine is used during surgery

40

What does Prazosin do?

-dilates arterioles and veins by blocking alpha1 adrenoceptors
-used where other therapy has proven ineffective or unacceptable
-used also in the treatment of benign prostatic hyperlplasia

41

Unwanted effects of prazosin

postural hypotension (fades)
retrograde ejaculation (relaxation of bladder neck)

42

What is benign prostatic hyperplasia?

Swelling of prostate that districts uretha, resulting in patient being unable to release urine