Adrenergic Drugs

Question 1

what is the major mechanism for termination of action of adrenergics?

Answer 1

reuptake

Question 2

what are the ways that drugs affect adrenergic transmission?

Answer 2

norepinephrine synthesis
vesicle uptake of neurotransmitter
release of neurotransmitter
receptor interactions
reuptake
metabolism

Question 3

what are the adrenergic receptors?

Answer 3

alpha receptors: alpha1 and alpha2
beta receptors: beta1, beta2, and beta3
dopamine receptors: D1-D5

Question 4

what is the response to receptor activation of alpha1 receptors?

Answer 4

contraction (arteries, veins, uterus)

Question 5

what is the response to receptor activation of alpha2 receptors?

Answer 5

inhibit norepinephrine release at presynaptic nerve endings
decrease sympathetic tone at postsynaptic in CNS

Question 6

what is the response to receptor activation of beta1 receptors?

Answer 6

increased heart rate and force of contraction

Question 7

what is the response to receptor activation of beta2 receptors?

Answer 7

dilation of arterioles
relaxation of bronchial and uterine smooth muscle

Question 8

what is the response to receptor activation of beta3 receptors?

Answer 8

increased lipolysis in lipocytes

Question 9

what is the response to receptor activation of D1 receptors?

Answer 9

dilation of arterioles of kidney and mesentery

Question 10

what is essential in activation of alpha1 receptors?

Answer 10

calcium

Question 11

what happens intracellularly after an alpha2 receptor is activated?

Answer 11

decrease in cAMP

Question 12

what happens intracellularly after a beta receptor is activated?

Answer 12

increase in cAMP

Question 13

how can beta2 receptors and alpha1 receptors lead to opposite actions through a similar route?

Answer 13

MLC is phosphorylated in alpha1, leading to smooth muscle contraction
MLC is not phosphorylated in beta2, leading to smooth muscle relaxation

Question 14

what is the mechanism of action for alpha1 receptors?

Answer 14

increase calcium

Question 15

what is the mechanism of action for alpha2 receptors?

Answer 15

decrease cAMP
open potassium channels
close calcium channels

Question 16

what is the mechanism of action for beta1, beta2, and beta3 receptors?

Answer 16

increase cAMP
increased cAMP increases calcium in heart

Question 17

what is the mechanism of action for D1 receptors?

Answer 17

increase cAMP

Question 17

what is the mechanism of action for D2 receptors?

Answer 17

decrease cAMP
open potassium channels
decrease calcium flux

Question 18

what are the systemic effects of the sympathetic nervous system? what receptors lead to what?

Answer 18

increased blood pressure: alpha1 and beta1
decreased blood pressure: beta2
increased kidney perfusion: D1
sedation and decreased blood pressure: alpha2

Question 19

what are some direct acting adrenergic agonists?

Answer 19

epinephrine
norepinephrine
isoproterenol
phenylephrine
dobutamine
terbutaline

Question 20

what are some indirect acting adrenergic agonists?

Answer 20

tyramine
phenylpropanolamine
amphetamine

Question 21

what are some mixed acting adrenergic agonists?

Answer 21

ephedrine
dopamine

Question 22

how do alpha1 adrenergic agonists affect blood pressure?

Answer 22

increases blood pressure

Question 23

how do adrenergic agonists (mostly beta1) affect the heart?

Answer 23

increase force of contraction
increase rate of contraction
increase cardiac output
increase excitability
increase automaticity
decrease efficiency

Question 24

how does phenylephrine (alpha1) affect heart rate and blood pressure?

Answer 24

increase blood pressure compensatory bradycardia

Question 25

how does epinephrine (alpha, beta1 and beta2) affect heart rate and pressure?

Answer 25

increase blood pressure but not as much as alpha1 increase rate

Question 26

how does isoproterenol (beta1 and beta2) affect blood pressure and heart rate?

Answer 26

beta1 initially increases blood pressure beta2 then drops blood pressure and raises heart rate

Question 27

how do adrenergic agonists affect the gastrointestinal system?

Answer 27

motility decreased by alpha2 and beta2 increased sphincter contraction by alpha1

Question 28

what are the metabolic effects of adrenergic agonists?

Answer 28

increase blood glucose by beta2 decrease insulin secretion by alpha2 stimulate glucagon secretion by beta2 high concentration: metabolic acidosis and decrease serum potassium

Question 29

what are the clinical applications of adrenergic agonists?

Answer 29

anaphylactic shock and hypersensitivity reactions (epinephrine) congestive heart failure (dobutamine and dopamine) AV block cardiac and septic shock (dopamine) cardiac arrest (epinephrine) local hemostatic agents (alpha1agonists) prolong local anesthetic effects (epinephrine) nasal decongestants (alpha1 agonists) urinary bladder sphincter incompetence (alpha1 agonist, ephedrine, phenylephrine) bronchodilator (terbutaline, beta2 agonists) open-angel glaucoma (epinephrine) reduce synechia (iris to cornea) formation (alpha1 agonist, phenylephrine) sedation (alpha2 agonist)

Question 30

what are the adverse effects of adrenergic agonists?

Answer 30

CNS: anxiety, fear, restlessness cardiovascular and other: cardiac arrhythmia, tachycardia, reflex bradycardia, hypertension, tachyphylaxis, nasal irritation, local necrosis

Question 31

what are the pharmacological effects of adrenergic alpha-antagonists on the cardiovascular system?

Answer 31

decrease blood pressure epinephrine reversal

Question 32

what are the clinical applications of adrenergic alpha-antagonists with the cardiovascular system?

Answer 32

hypertension, congestive heart failure

Question 33

what do adrenergic beta-antagonists do to the cardiovascular system?

Answer 33

decrease heart rate (anti beta1) decrease force of contraction (anti beta1) decrease AV conduction (anti beta1) decrease blood pressure (anti beta1 and beta2)

Question 34

what do adrenergic beta-antagonists do to the respiratory system?

Answer 34

bronchoconstriction (anti beta2)

Question 35

what do adrenergic beta-antagonists do to the eye?

Answer 35

reduce intra-ocular pressure (anti beta2)

Question 36

what are the clinical applications of adrenergic beta-antagonists with the cardiovascular system?

Answer 36

cardiac arrhythmia (anti beta1) hypertension (anti beta1) hypertrophic cardiomyopathy in cats (anti beta1)

Question 37

what are the clinical applications of adrenergic beta-antagonists with ophthalmology?

Answer 37

glaucoma (timolol)

Question 38

what are the adverse effects of adrenergic alpha-antagonists?

Answer 38

hypotension (anti alpha1) reflex tachycardia (anti alpha1) CNS stimulation (anti alpha2)

Question 39

what are the adverse effects of adrenergic beta-antagonists?

Answer 39

decreased cardiac output (anti beta1) bradycardia (anti beta1) bronchospasm (anti beta2)

Question 40

what do alpha1 adrenergic agonists do to the gastrointestinal system?

Answer 40

increase sphincter tone

Question 41

what do alpha2 and beta2 adrenergic agonists do to the gastrointestinal system?

Answer 41

decrease motility