Presynaptic Drugs

Question 1

Rate limiting step of ACh synthesis

Answer 1

Transport of choline into pre-synaptic nerve endings by a Na+ choline co-transporter

Question 2

ACh is stored in ____.

Answer 2

Nerve terminal vesicles

Question 3

ACh is released when ____

Answer 3

Stimulated by an action potential/Ca2+ influx; causes exocytosis of ACh vesicle

Question 4

OnabotulinumtoxinA (Botox) function

Answer 4

Inhibit ACh release

Question 5

OnabotulinumtoxinA MOA

Answer 5

Neurotoxic proteases endocytosed into cholinergic nerve terminals and inactive SNAP-25 needed to dock vesicle membrane

Question 6

OnabotulinumtoxinA causes _____ paralysis and inactivates _____ glands

Answer 6

Flaccid; sweat

Question 7

OnabotulinumtoxinA duration of action

Answer 7

3-4 months

Question 8

Clinical uses of OnabotulinumtoxinA

Answer 8

Muscle spasms
Cosmetic
Hyperhidrosis
Migraines
Overactive bladder

Question 9

Sides effect of OnabotulinumtoxinA

Answer 9

Dysphasia
Difficulty breathing
Muscle weakness
Urinary retention

Question 10

OnabotulinumtoxinA black box warning

Answer 10

Distant spread beyond injection site

Question 11

What tissues are M3 receptors found in?

Answer 11

Smooth muscle, glands, endothelium

Question 12

M3 receptors are a ____ G-protein coupled receptor

Answer 12

Gq (activate PLC to initiate cascade to increase Ca2+)

Question 13

M2 receptors are found in the _____

Answer 13

Heart

Question 14

M2 receptors are ___ G-protein coupled receptors

Answer 14

Gi ( decrease cAMP, increase K+ efflux to cause hyperpolarization)

Question 15

Prototype muscarinic ACh agonist

Answer 15

Muscarine

Question 16

Muscarine activates ____

Answer 16

All muscarinic receptor types

Question 17

Prototype muscarinic ACh antagonist

Answer 17

Atropine

Question 18

Atropine blocks ____

Answer 18

All muscarinic receptor subtypes

Question 19

Nicotinic receptors are ____ ion channels

Answer 19

Ligand-gated

Question 20

When stimulated nicotinic receptors increase ___ permeability, causing ______

Answer 20

Na+; depolarization

Question 21

Nn receptors are located in _____

Answer 21

Ganglia and adrenal medulla

Question 22

Nn receptor high affinity agonist

Answer 22

Nicotine

Question 23

Nn receptor prototype antagonist

Answer 23

Mecamylamine

Question 24

Nm receptors are located in the ______ junction

Answer 24

Neuromuscular

Question 25

Nm receptor low affinity agonist

Answer 25

Nicotine

Question 26

Nm receptor prototype antagonist

Answer 26

D-tubocurarine

Question 27

After stimulating N receptors, nicotine ____ the receptor

Answer 27

Desensitizes (acts like an antagonist)

Question 28

What enzyme rapidly hydrolyzes ACh to terminate cholinergic neurotransmission?

Answer 28

Acetylcholinesterase (AchE)

Question 29

Inhibition of AChE causes ACh to ____

Answer 29

Accumulate in the synapse, resulting in increased stimulation and then desensitization

Question 30

Butyrylcholinesterase function

Answer 30

Drug metabolizing enzyme that controls plasma levels of choline ester drugs

Question 31

Synthesis of Catecholamine Pathway

Answer 31

Tyrosine —> dopa —> dopamine —> norepinephrine—> epinephrine

Question 32

Tyrosine is converted to dopa in the ____

Answer 32

Cytosol

Question 33

Dopamine is converted to norepinephrine in ____

Answer 33

Vesicles

Question 34

Norepinephrine is converted to epinephrine in the ___ of the ____.

Answer 34

Cytosol; adrenal medulla

Question 35

Catecholamines are degraded by ____ if they are not stored

Answer 35

Mitochondrial monoamine oxidase

Question 36

Catecholamines are actively transported into vesicles by ___

Answer 36

Vesicular monoamine transporter-2 (VMAT-2)

Question 37

Tyramine can cause a ___ crisis

Answer 37

Hypertensive

Question 38

Tyramine mechanism

Answer 38

Displaces NE from storage vesicles; increased cytosolic NE triggers it’s release by reverse transport through NET

Question 39

Patients on MAOIs need to have ____ restrictions to reduce intake of ____

Answer 39

Dietary; tyramine (wine and cheese effect)

Question 40

Methyldopa is a prodrug that is converted to ____

Answer 40

Methyl-NE

Question 41

Methyldopa MOA

Answer 41

Lowers BP by decreasing sympathetic outflow from the CNS to the heart, vasculature, and kidneys

Question 42

Methyldopa clinical use

Answer 42

Gestational hypertension

Question 43

Methyldopa side effects

Answer 43

Sedation Dry mouth Edema Autoimmune hemolytic anemia (long term use)

Question 44

Pre-synaptic adrenergic receptor subtype

Answer 44

Alpha 2

Question 45

Post synaptic adrenergic receptor subtypes

Answer 45

Alpha 1, Beta 1,2, and 3

Question 46

All adrenergic receptors are coupled to ____

Answer 46

G Proteins

Question 47

Alpha 1 receptors are G_

Answer 47

Gq

Question 48

Alpha 2 receptors are G_

Answer 48

Gi

Question 49

All Beta receptors are G_

Answer 49

Gs

Question 50

Beta 1 receptors cause ___ Beta 2 receptors cause ___

Answer 50

Contraction Relaxation

Question 51

Monoamine oxidase inhibitors (MAOIs) are used for:

Answer 51

Depression Parkinson’s

Question 52

Cocaine blocks ____ from being reabsorbed

Answer 52

Norepinephrine

Question 53

____ clears circulating Catecholamines

Answer 53

Catecholo-methyltransferase (COMT)

Question 54

Major Catecholamine metabolite excreted in urine

Answer 54

VMA