SNS drugs

Question 1

where are andrenergic receptors found

Answer 1

1. CNS and SNS

2. presynaptically on neuron or post-synaptically on effector organ

Question 2

where do catecholamines come from

Answer 2

synthesized from tyrosine in sympathetic nerve endings

Question 3

what are drugs that turn on SNS

Answer 3

1. sympathicomimetics

2. a or B angonists

Question 4

what are drugs that turn off SNS

Answer 4

1. sympatholytics

2. a or B blockers

Question 5

what are receptor types for each SNSr

Answer 5

a1 - Gq and i/o
a2 - Gi/o
B - Gs

Question 6

tissues for a1

Answer 6

1. vascular smooth muscle
2. GU and GI smooth muscle
3. heart
4. liver

Question 7

tissues for a2

Answer 7

1. pancreatic B cells
2. platelets
3. nerve
4. vascular smooth muscles

Question 8

actions of a1 agonists

Answer 8

1. vasoconstriction
2. increased vascular resistance
3. enlarged pupils
4. sphincter closure

Question 9

actions of a2 agonists

Answer 9

inhibit cAMP

- inhibits Ca channels , NE release, Ach release, insulin release

Question 10

tissues for B1

Answer 10

1. heart

2. juxtaglomerular cells

Question 11

tissues for B2

Answer 11

1. bronchi
2. skeletal muscle
3. liver

Question 12

tissues for B3

Answer 12

1. adipose

Question 13

actions of B1 agonists

Answer 13

Gs > cAMP> opening of Ca channel - contractions

1. tachycardia
2. myocardial contraction
3. lipolysis
4. renin release

Question 14

actions of B2 agonists

Answer 14

Gs > cAMP > PKA phosphoylate MLCK > inactive > relax

1. vasodilation
2. decrease peripheral resistance
3. bronchodilation
4. glycogenolysis
5. release of glucagon

Question 15

3 potential actions of sympathomimetics

Answer 15

1. direct action - stim G receptor
2. indirect - affect synthesis, storage, release of actitivy
3. mixed

Question 16

what are direct acting sympathomimetics (2)

Answer 16

catechoamines 
1. rapid onset
2. breif action
3. paraenterally
non - catecholamines

Question 17

5 important catecholamines

Answer 17

1. NE
2. E
3. dopa
4. isoproterenol
5. dobutamine

Question 18

where does NE act and what does it do (2)

Answer 18

1. a>B1»B2,3
2. increase MAP and PVR
3. increase HR but reflex bradycardia

Question 19

where does E act and what does it do (2)

Answer 19

1. low dose mostly B and high dose mostly a

2. increase inotropy and chronotropy (B1), bronchodilates (B2), hyperglycemia, drops peripheral resistance (B2)

Question 20

what does dopamine do

Answer 20

1. vasodilates peripheral renal, mesenteric, coronary vascular beds via D1
2. inhibs NE release
3. at high does B1 effects the biggest
4. at higher dose a1 is most - good for treatment of shock

Question 21

what are a1 agonists (phenyephrine) used for

Answer 21

treatment of shock, nasal decongestants

Question 22

what are a2 agonists (clonadine) used for

Answer 22

hypertension by acting on CNS to inhibit sympathetic output

1. CNS - inhibits excitatory outflow
2. peripheral - inhibits release of catecholamines

Question 23

what are B1 agonists (dobutamine) used for

Answer 23

increase cardiac output - ionotropic effects more significant

Question 24

what are B2 agonists (salbutamol) used for

Answer 24

aerosols for bronchodilation

Question 25

what is a non-seletive B agonist

Answer 25

isoproterenol | - most prominent effects are B, but rarely used because of lack of selectivity

Question 26

what does and indirect andrenergic agonist (amphetamine) do

Answer 26

reverses the vesicular monoamine transporter > more NE and dopa - vasoconstriction, MAP, ionotropy - wakefulness, euphoria, anxiety, hypertension

Question 27

what are mixed sympathomimetics

Answer 27

ephedrine and pseudoephedrine | - increase release of NE and stim a1, B1, B2

Question 28

2 classes of sympatholytics and examples

Answer 28

1. direct - a and B blockers | 2. indirect - decrease release, change storage, decrease synthesis

Question 29

2 types of a blockers

Answer 29

1. reversible - can be displaced by agonists - phenotolamine, prazolin 2. irreversible - covalent bond - phenoxybenzamine

Question 30

what do non-selective a blockers do

Answer 30

- both a1 and a2 - lower PVR and reflex tachycardia - more profound effects when standing - more NE released because of a2 blockade

Question 31

what do a1 selective blockers do

Answer 31

- good for hypertension - lower PVR - fewer adverse effects - lower lipid levels - ___-zosins

Question 32

what do a1A selective blockers do

Answer 32

- tamulosin | - treatment of BPH by causing vasodilation of the prostate vascular smooth muscle

Question 33

what are effects of non-selective B-blockers (propranolol)

Answer 33

- lower ionotropy, chronotropy, CO, SA and AV activity | - brochoconstrict problematically

Question 34

what are B1 blockers good for

Answer 34

avoid bronchoconstriction | - metoprolol, atenolol, bisprolol