Pharmacology ANS

Question 1

Muscarinic receptor agonist

Answer 1

pilocarpine-glaucoma
bethanechol-reverse gi post op depression/urinary retention
methacholine-belladona poisioning dx
carbachol
muscarine-mushroon highly muscarininc

Question 2

cholinesterase reversible inhibitors

Answer 2

Edrophonium- diagnostic for MG
Physostigmine-short acting glaucoma crosses BBB
echothiopathe-long acting glaucoma
Neostigmine-no BBB
Pyridostigmine- 3 to 6 hrs of action

Question 3

cholinesterase irreversible inhibitors

Answer 3

pesticides, nerve gases

Question 4

Uses of Ach inhibitors

Answer 4

1. Eye-miosis, accomodation block, glaucoma, combination with alpha agonist or beta antagonist
2. GI-motility and atony of urinary bladder
3. NMJ-myasthenia gravis tc snd Dx
4. Reverse toxicity by anticholinergic agents

Question 5

Cholinesterase inhibitor intoxication

Answer 5

Mild poisoning- Atropine 1-2 mg and pralidoxime 1 gram infused slowly.
Severe- Atropine sulfate 2-4 mg and pralidoxime give diazepam if convulsions

Question 6

Anticholinergics

Answer 6

Belladona alkaloids-Atropine, scopolamine, homatropine

Synthetic- ipratropium, benztropine, glycopyrolate

Question 7

examples of baroreceptor reflex

Answer 7

carotid endarterectomy-carotid sinus manipulation

mediastinoscopy- pressure in the transverse aortic arch

Question 8

norepinephrine

Answer 8

alpha 1, alpha 2 and beta 1 receptors
ideal for low SVR states such as sepsis or post CPB, no in cardiogenic shock
dose: 0.02-0.4 mcg/kg/min
low dose: beta 1
High dose: alpha 1 and 2 and b1 receptors

Question 9

Epinephrine

Answer 9

Low dose 0.01-0.03 mcg/kg/min

Question 10

Long-term use of these agents leads to supersensitization and up-regulation of receptors; with abrupt discontinuation of either drug, an acute withdrawal syndrome manifested by a hypertensive crisis can occur?

Answer 10

Precedex and clonidine

Question 11

Discontinuation of β-blocker therapy for 24-48 hr may trigger a withdrawal syndrome characterized by?

Answer 11

Hypertension, tachycardia, angina pectoris

Question 12

Drug that inhibits COMT

Answer 12

entecapone

Question 13

NE transporter blocker

Answer 13

cocaine, TCA

Question 14

What is reserpine?

Answer 14

Prevents storage of NE

Question 15

MAO inhibitors

Answer 15

pargyline, tranylcypromine, selegiline

Question 16

Inhibitation of NE uptake II

Answer 16

glucocorticoids

Question 17

Adrenergic Agonist selective

Answer 17

Phenylephrine
Dobutamine
Terbutaline
clonidine

Question 18

Adrenergic agonist nonselective

Answer 18

oxymetazoline
isoproterenol
epinephrine
norepinephrine

Question 19

Mixed agent

Answer 19

Ephedrine

Question 20

Indirect acting adrenergic agonist

Answer 20

releasing agent-amphetamines, tyramine
uptake inhibitor- cocaine
MAO/COMT inhibitors-pargyline, entecapone

Question 21

actions and clinical uses of Ach inhibitors

Answer 21

EYE
GI tract
NMJ
Reverse toxicity of anticholinergic agents

Question 22

Which drugs increase heart rate the most in a patient with a heart transplant?

Answer 22

Epinephrine and Isoproterenol

Question 23

What is Shy-drager syndrome?

Answer 23

Autonomic dysfunction as well as degeneration of the locus coerulus, intermediolateral column of the spinal cord, and the peripheral autonomic nerves

Question 24

What is phenoxybenzamine?

Answer 24

Irreversible non selective alpha blocker (noncompetitive antagonist)
Also antagonism of Ach, 5HT and histamine.

Question 25

What is phentolamine?

Answer 25

Competitive nonselective alpha blocker. Cholinomimetic, adrenomimetic, histamine like reactions

Question 26

How does dobutamine work and when is it indicated?

Answer 26

Dobutamine is b1 selective and it is used as a short term treatment of cardiac decompensation after surgery or patients with CHF or MI

Question 27

What is isoproterenol?

Answer 27

Synthetic catecholamine It is a B1 and B2 agonist derived from dopamine. It is used as a bronchodilator in asthma and complete heart block or cardiac arrest

Question 28

Explain how dopamine works on the receptors

Answer 28

At doses between 0.5 to 2 mg/kg/min the dopamine-1 receptors are stimulated resulting in renal and mesenteric vascular dilation. At doses between 2 to 10 mg/kg/min, the b1 effects predominate with increases in cardiac contractility and cardiac output. At doses greater than 10 mg/kg/min, the a1 effects predominate, and there is generalized vasoconstriction negating any benefit to renal perfusion.

Question 29

What are some synthetic cathecholamines?

Answer 29

Isoproterenol, dobutamine, feoldopam

Question 30

Endocrine and metabolic effects or epinehrine?

Answer 30

increased blood glucose, increased lactate, and increased fatty acids

Question 31

Describe direct and indirect effects of dopamine

Answer 31

Dopamine binds to the adrenergic receptors on target cells to cause a direct adrenergic effect. Dopamine also causes the release of endogenous norepinephrine from storage vesicles. This is referred to as dopamine’s indirect sympathomimetic effect

Question 32

Drugs that indirectly stimulate the SA node will not increase HR are

Answer 32

Atropine, glycopyrrolate, ephedrine

Question 33

How does glucagon increases HR

Answer 33

It increases cAMP independent of beta receptor stimulation

Question 34

Mechanism of action of methylene blue

Answer 34

inhibits nitric oxide pathway