Sympathomimetics

Question 1

Where are most alpha-2 receptors located?

Answer 1

On the presynaptic terminal

Question 2

Are catecholamines water soluble or water insoluble?

Answer 2

Water soluble

Question 3

Norepinephrine

Answer 3

Catecholamine, direct on A1 and A2, less on some B1

Question 4

Epinephrine

Answer 4

Catecholamine, direct on A1, A2, B1, B2

Question 5

Isoproterenol

Answer 5

Catecholamine direct on B1 and B2

Question 6

Dopamine

Answer 6

Catecholamine direct on A1,B1,B2 and DA (renal vessels)

Question 7

Dobutamine

Answer 7

Catecholamine, direct on B1, others

Question 8

Phenylephrine

Answer 8

Non-catecholamine, direct on A1

Question 9

Tetrahydrozoline

Answer 9

Non-catecholamine, direct on A1

Question 10

Nephazoline

Answer 10

Non-catecholamine, direct on A1

Question 11

Oxymetazoline

Answer 11

Non-catecholamine, direct on A1

Question 12

Ritodrine

Answer 12

Non-catecholamine, direct on B2 more than B1

Question 13

Metaproterenol

Answer 13

Non-catecholamine, direct on B2 more than B1

Question 14

Albuterol

Answer 14

Non-catecholamine, direct on B2 more than B1

Question 15

Salbutamol

Answer 15

Non-catecholamine, direct on B2 more than B1

Question 16

Salmeterol

Answer 16

Non-catecholamine, direct on B2 more than B1

Question 17

Formoterol

Answer 17

Non-catecholamine, direct on B2 more than B1

Question 18

Terbutaline

Answer 18

Non-catecholamine, direct on B2 more than B1

Question 19

Clonidine

Answer 19

Non-catecholamine, direct on A2

Question 20

Ephedrine and pseudoephedrine

Answer 20

Non-catecholamine, indirect on a and b (increased release)

Question 21

Amphetamine

Answer 21

Non-catecholamine, indirect on a and b (increased release)

Question 22

Cocaine

Answer 22

Non-catecholamine, indirect on a and b (decreased uptake)

Question 23

Tyramine

Answer 23

Non-catecholamine, indirect on a and b

Question 24

What suffix is commonly associated with beta-agonists?

Answer 24

ol

Question 25

What response do blood vessels give to alpha-beta agonists at different concentrations?

Answer 25

Low concentration - beta response, high concentration - alpha response

Question 26

Which sympathomametics cross the blood brain barrier well and why?

Answer 26

Amphetamine and ephedrine because they do not have OH groups (they cause CNS stimulation in the brain)

Question 27

Which isomer is more potent in sympathomimetics

Answer 27

L-isomer in periphery, d-isomer in CNS

Question 28

What chemical change increases a drugs beta activity?

Answer 28

N-alkylation

Question 29

A botched IV infusion with a type of sympathomimetic can damage tissue. What type and why?

Answer 29

Alpha agonist. Because they cause BV constriction, if they end up the tissue you can get necrosis

Question 30

What happens to catecholamines if exposed to air?

Answer 30

Solution can turn pink, drug has deteriorated

Question 31

Give the effects of an alpha1 agonist on the lung, GI, Heart, BVs, Eye, Uterus, Glands, Liver, Pancreas, Skeletal muscle, and CNS

Answer 31

Lungs - none, GI - decreased activity, Heart - none, BVs - constriction, Eye - Mydriasis, Uterus - none, Glands - secretion, Liver - Glycogenolysis, gluconeogenesis, Pancreas - none, Skel muscle - none, CNS - alertness

Question 32

Give the effects of a beta1 agonist on the lung, GI, heart, BVs, eye, uterus, glands, liver, pancreas, skel muscle, CNS, and kidney

Answer 32

Lung - none GI - none, Heart - Increased HR, contract, velocity, BVs - none, Eye - increased inflow, uterus - none, glands - none, liver - none, pancreas - none, skel muscle - none, CNS - fatigue, hunger, kidney - renin

Question 33

Give the effects of a beta2 agonist on lungs, GI, heart, BVs, Eye, uterus, glands, liver, pancreas, skel muscle, CNS, and kidney

Answer 33

Lungs - Bronchorelaxation, GI - decreased activity, heart - increased HR, contract, velocity (less than B1), BVs - dilation, eye - increased inflow, uterus - relaxtion, glands - none, liver - glycogenolysis and gluconeogenesis, pancreas - insulin secretion increased, skel muscle - increased activity, CNS - fatigue, hunger, kidney - renin

Question 34

What is the only end organ effect of alpha2 agonism?

Answer 34

Decreased insulin secretion from the pancreas

Question 35

Why is hyperthyroidism a contraindication for beta agonists?

Answer 35

Because T3 regulates B2 receptors on heart (increases their sensitivity)

Question 36

Why is Raynauds disease a contraindication for alpha agonists?

Answer 36

Because the blood vessels are already constricted in Raynauds and alpha agonists constrict them more

Question 37

What type of sympathomimetic increases blood glucose?

Answer 37

B2 agonists (this is despite an increase in insulin secretion that occurs with B2 agonism)

Question 38

Give the effect of norepinephrine on blood pressure and the reason for this effect

Answer 38

Increase diastolic, smaller increase in systolic and MBP. Due to increase in peripheral resistance

Question 39

Give the effect of epinephrine on blood pressure and the reason for this effect

Answer 39

Increase systolic, diastolic no change, increase MBP. Due to increase in HR and CO

Question 40

Give the effect of isoproterenol on blood pressure and the reason for this effect

Answer 40

Increase systolic, decrease diastolic and mean (Peripheral Resistance decreases, CO up initially but down due to pooling)

Question 41

Give the effect of dopamine on blood pressure and the reason for this effect

Answer 41

Increase systolic, no change in diastolic, increase MBP. Due to increase HR and CO (no change in resistance except for renal dilation)

Question 42

Three vascular uses of alpha agonists

Answer 42

Nasal decongestion, stopping superficial bleeding, prevent spread of local anesthetic

Question 43

What drug is given for CHF and why?

Answer 43

Dobutamine (a selective B1 agonist). Has fewer other effects while having the desired effect (increased CO)

Question 44

What does histamine cause during anaphylactic shock and what is given to combat this (explain why)

Answer 44

Histamine causes bronchoconstriction and vasodilation. Epinephrine is given to combat that (alpha and beta agonist) because it causes bronchorelaxation (B2) and vasoconstriction (A1)

Question 45

What is the mechanism of open angle glaucoma and what is given to combat this?

Answer 45

Problem with outflow so give a parasympatheticomimetic to contract the cilliary body and increase ourflow or a beta antagonist to decrease inflow.

Question 46

What autonomic drug might you give to reduce premature contractions?

Answer 46

A beta 2 agonist