SNS

Question 1

What affect does CNS drugs have on the CVS?

Answer 1

Increase CO by:
increase HR
increase myocardial contraction
vasoconstriction in skeletal muscle

Question 2

What affect does CNS drugs have on the respiratory system?

Answer 2

increase respiratory rate

bronchioles dilate

Question 3

What other affects does CNS drugs have on the body?

Answer 3

mydriasis (dilation)
decreases GIT motility
decreased saliva
bladder sphincter contraction
hyperglycemia

Question 4

what does Adrenergic receptor: alpha 1 do ? (think blood vessel)

Answer 4

mydriasis (dilation)
decreased GIT motility
splenic contraction ‘stitich’
urinanty retention (bladder sohin

Question 5

what does Adrenergic receptor: alpha 2 do?

Answer 5

-ve feedback on release of noradrenaline
vasodilation
-ve feedback on SNS in CNS

Question 6

what does Adrenergic receptor: Beta 1 do? (think heart)

Answer 6

increases myocardial contraction force
increases HR
this increases CO
inotropic and chronotropic

Question 7

what does Adrenergic receptor: Beta 2 do ? (think lungs)

Answer 7

bronchodilation
skelteal muscle
vasodilation

Question 8

What are uses of Adrenaline?

Answer 8

Anaphylaxis - B2 agonism (bronchodilation) - has a short DOA, so may need a repeated dose

CRI infusions for dangerous hypertension - utilised alpha 1 (vasoconstriction) effect, increases BP - give as infusion as short DOA

Control of minor bleeding - causes less blood in peripheral end. It Cannot control damage to large vessels

Added to other drugs to slow absorption e.g. local anaesthetics

Cardiac arrest B1 increases CO - adjunctive therapy

Question 9

What are the uses of Noradrenaline?

Answer 9

Less B2 affect (lungs) than adrenaline = doesn’t cause vasodilation of skeletal muscle = more effective for cardiac arrest and hypotension

if ACP has been used as a pre-med than need to use NADr

Question 10

Uses of Dobutamine

Answer 10

used on many horses under volatile GA
B1 effect (increases CO) - this improves myocardial contraction but minimal effect on HR. 
Short acting so give as an infusion
only used short term (i.e during anaesthesia) as body down regulates the number of B receptors.

Question 11

What are the used of Terbutaline?

Answer 11

B2 against (bronchodilator/vasodilation)
used to dilate airways
can be given PO, aerosol or SC

Question 12

Salbutamol - asthma puffer

Answer 12

B2 agonist causes bronchodilator

improves ventilation. Used in equine respiratory (COPD)

Question 13

Clenbuterol -

Answer 13

important B2 - bronchodilator/skeletal muscle vasodilation. B2 agonist primarily affects respiratory system but can cause uterine relaxation. Can be used to facilitate callings. Can be given injection or PO

Question 14

What is Phenylopropanolamine used for?

Answer 14

URINARY INCONTINENCE
moa: alpha 1 effect: constricts urethral smooth muscle and therefore retaining urine.
B2 effect: will relax detrusor muscle which will allow improved bladder filling.

Use: bitches have on-label use but it is also used in male/females cats/dogs

Contraindications: do not use in case of diabetes hypertension, tachycardia due to the alpha 1 affects - increase vasoconstriction (hypertension) and increase HR (tachycardia) CV affects and it releases glycogen from the liver (diabetes)

Question 15

Adrenergic ANTAGONIST

Answer 15

Yohimbine - non selective
Propanol - selects for B1,2 so caution with airway disease
Atenol - selective for B1

Propanol and Atenolol - B antagonistic effect
“the better blockers”
Antiarrhythmics via their -ve effect in excessive sympathetic stimulation of the heart.