ANS Drugs (Exam 1)

Question 1

Neostigmine

Answer 1

inj, cattle horses pigs sheep
rumen atony, intestinal motility in horses, reversal of neuromuscular blockers. sometimes used to tx myasthenia gravis (immediate acting)

Question 2

Pyridostigmine

Answer 2

same MoA as neostigmine but longer duration. Used to tx myasthenia gravis in small animals
Oral

Question 3

Edrophonium

Answer 3

anticholinesterase

used in dx of myasthenia gravis

Question 4

Carbamate Insecticides

Answer 4

Muscarinic signs/DUMBBELS then nictonic excitment and eventually nicotinic blockade.
Likely to cross the blood brain barrier leading to CNS excitement/seizures.

Question 5

Organophosphate insectacides

Answer 5

clinical signs similar to carbamate toxicity but metabolize slower and bond irreversably. Can be tx w/ atropine.

Question 6

Atropine

Answer 6

nonspecific muscarinic antagonist (dry secretions, slow Gi, increase HR, dilate airways, dilate pupils)
Used most to tx bradycardias and OP/Carbamite toxicity

Question 7

Bethanechol

Answer 7

Oral med for contraction of detrusor m.
Muscarinic agonist w/ some selectivity for M3
Direct parasympathomimetic

Question 8

Glycopyrolate

Answer 8

like atropine but doesn’t cross BBB
Slower onset and longer duration
Preferred in rabbits

Question 9

Oxybutynin and Propantheline

Answer 9

Urinary antispasmodic
Direct antimuscarinic and spasmolytic effects on smooth muscle (bladder and large intestine)
Used for detrusor hyperreflexia

Question 10

Epinerphrine

Answer 10

activates all adrenergic receptors

used for cardiac arrest, anaphylaxis/anaphylactiodd rxns

Question 11

Norepinephrine

Answer 11

alpha agonist, b-1 at higher doses, minimal b-2

increases mean blood pressure can cause a baroreceptor reflex (reflex vagal bradycardia)

Question 12

Dopamine

Answer 12

acts directly/indirectly on alpha and beta-1 receptors and dopamine receptors.

Question 13

Low doses of dopamine act on _____ causing ______

Answer 13

peripheral dopamine receptors

dilation of vascular beds

Question 14

Moderate levels of dopamine activate ________ causing _________

Answer 14

b-1 receptors

+ inotropic and chronotropic effects

Question 15

High doses of Dopamine activate ________ and cause ______

Answer 15

a-1 receptors

release of NE leading to vasoconstriction

Question 16

Dobutamine

Answer 16

selective beta-1 agonist

+ inotrope

Question 17

Isoproterenol

Answer 17

nonselective b1&2 agonist

used to tx bradyarrhythmias or acute bronchoconstriction

Question 18

Phenyephrine

Answer 18

selective a-1 agonist
sytemic- vasopressor
local- vasoconstriction
local eye- mydriatic

Question 19

Ractopamine

Answer 19

agonist at b-3 (most) and b1&2

reduces fat deposition and increase muscle deposition food animals

Question 20

Albuterol/Salbutamol

Answer 20

Selective b-2 agonist

aerosol bronchodilator

Question 21

Salmeterol

Answer 21

b-2 agonist inhaler bronchodilator

Question 22

Clenbuterol

Answer 22

selective b-2 agonist

syrup for horses w/ COPD and mucokinetic agent

Question 23

Tetrabutaline

Answer 23

selective b-2 agonist bronchodilator

oral bioavail. in horse is terrible

Question 24

Isoxsuprine

Answer 24

b-2 agonist that acts as a peripherial vasodilator (skeletal muscle, distal limb) and causes uterine relaxation
Sometimes used as a tocolytic in cattle

Question 25

PPA

Answer 25

indirectly increases release of NE in bladder neck/urethra direct a-1 agonist used to tx small animals (dogs mostly) for urethral sphincter hypotonus Can be used synergistically w/ estrogens

Question 26

Ephedrine/Pseudoephedrine

Answer 26

indirect release of NE and some direct a-1 and beta activation vasocontriction, cardiac stimulation, bronchodilation, urinary sphincter contraction, mydriasis) Can be in some chinese herbal therapies and OTC

Question 27

Phenoxybenzamine

Answer 27

``` nonspecific alpha antagonist the irreversibly binds used to tx urinary retension by relaxing the internal urethral sphincter (smooth muscle) manage pheochromocytoma (tumor of adrenal medulla) - manage hypertension and blood pressure spikes caused by catecholamine release ```

Question 28

Prazosin

Answer 28

alpha-1 antagonist tx urinary retention by relaxing smooth muscle sphincter greater effect and faster onset than phenooxybenzamine but potentially greater cardiovascular effects

Question 29

Propanolol

Answer 29

non-selective beta antagonist causes bradycardia through decreased firing of SA node, decreased AV node conduction, decreased cardiac output and myocardial oxygen demand used to tx supraventricular tachyarrhythmias

Question 30

Metoprolol

Answer 30

beta-1 selective antagonist | tx of methylxanthine (chocholate toxicity)

Question 31

Atenolol

Answer 31

b-1 selective antagonist | doesn't cross the BBB as much as propanolol

Question 32

Esmolol

Answer 32

selective beta-1 antagonist inj, doesn't cross BBB, 20 min duration of action lacks membrane-stabalizing effects of propanolol

Question 33

Reserpine

Answer 33

indirect acting sympatholytic blocks vesicular monamine transporters thus reducing norepinephrine uptake into vesicles and leading to reduced storage of NE and mediator depletion. Calming agents for equines in long stall rest

Question 34

Succinylcholine Phase I

Answer 34

activation of nicotinic Ach receptors similar to what Ach would do. Depolarizing NMB prolongs depolariztion of the motor end plate and prevents complete repolarization and thus stimulation by acetylcholine. During this phase muscle fasciculation (transient) followed by flaccid paralysis.

Question 35

Succinylcholine Phase II

Answer 35

In phase II the nicotinic receptors stay in an inactivated state and cannot respond to acetylcholine If phase II block is reached paralysis duration will be longer used for ET tube placement, prevention of laryngeal spasm

Question 36

Competitive neuromuscular blockers

Answer 36

competative antagonists w/ Ach for nicotinic receptors at the motor end plate that will result in more generalized flaccid muscle paralysis. Derived from curarie.

Question 37

Pancuronium

Answer 37

Competative aganoist w/ Ach for Nic. receptors- result in flaccid muscle paralysis significant amount excreted in urine, some metabolized by liver and a small amount excreted into bile

Question 38

Atracurium

Answer 38

undergoes spontaneous degradation in plasma (doesn't rely on hepatic or renal function for clearance)

Question 39

Vecuronium and Rocuronium

Answer 39

primarily metabolized by the liver and excreted in bile and urine

Question 40

How do you reverse competative neuromuscular blockers (curarie derived drugs)

Answer 40

cholinesterase inhibitors which may be combined w/ an antimuscarinic like atropine of glycopyrrolate to block muscarinic effects.

Question 41

How is Rocuronium's action terminated?

Answer 41

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