Calcium channel blockers

Question 1

What is the more determining factor for ion flow? Concentration gradient or Electrical gradient?

Answer 1

Electrical Gradient

Question 2

Where is K more highly concentrated?

Answer 2

Inside the cell

Question 3

Where is K more lowly concentrated?

Answer 3

Outside the cell

Question 4

Where is Na low?

Answer 4

Inside the cell

Question 5

Where is Na high?

Answer 5

Outside

Question 6

Ca+ is low where?

Answer 6

Inside the cell

Question 7

Ca+ is high where?

Answer 7

Outside the cell

Question 8

Most important Ca voltage gate you need to know for this class?

Answer 8

L-type, Ca 1.2

Question 9

What triggers contraction of Ca 1.2?

Answer 9

Ca2+ entry

Question 10

Ca 1.2 is found on what?

Answer 10

Cardiac and smooth muscle

Question 11

Ca 1.3 is found where?

Answer 11

SA/AV nodes, neurons, and endocrine cells

Question 12

What is a Ca1.3 a trigger for?

Answer 12

Hormone secretion

Question 13

Blockage of vascular smooth muscle leads to what?

Answer 13

Vasodilation

Question 14

Block of channels in cardiac muscle and SA/AV node results in what benefit?

Answer 14

Anti-arrhythmic

Question 15

What are intracellular stores of Ca2+ called?

Answer 15

RYR@ (ryanodine receptor 2)

Question 16

What REQUIRES Ca2+?

Answer 16

Cardiac and smooth muscle contraction

Question 17

What does Ca2+ release from SR bind to?

Answer 17

Troponin C

Question 18

Ca2+ binding of troponin c leads to what?

Answer 18

Displacement of tropomyosin

Question 19

Displacement of Tropomyosin causes what?

Answer 19

Allows myosin to bind actin

Question 20

What coupling allows for skeletal muscle contraction?

Answer 20

Coupling between Ca 1.1 and RYR1

Question 21

Does skeletal muscle contraction require extracellular Ca2+?

Answer 21

No

Question 22

Clinical applications for Calcium channel blockers? (3)

Answer 22

Angina Pectoris
Arrhythmia
Hypertension

Question 23

3 Distinct Chemical Classes of Calcium Channel blockers?

Answer 23

Dihydropyridines
Phenylalkylamines
Benzothiazepines

Question 24

Main structural feature of Dihydropyridines?

Answer 24

Dihydropyridine ring

Question 25

+ enantiomer of DHP does what?

Answer 25

Keeps gate closed and blocks current

Question 26

- enantiomer of DHP does what?

Answer 26

Won't let gate close and keeps current going

Question 27

When do you give Clevidipine?

Answer 27

When you want to treat hypertension immediately and oral administration isn't possible.

Question 28

What do you have to watch out for when giving clevidipine?

Answer 28

Allergy to soy and egg

Question 29

Where are DHPs most potent?

Answer 29

Relaxing smooth muscle such as coronary artery

Question 30

Do DHPs compromise cardiac function?

Answer 30

No

Question 31

DHPs are dependent on what for their potency?

Answer 31

Voltage of membrane

Question 32

Binding sites for DHPs, PAAs, and BZPs are what?

Answer 32

Linked, but not identical

Question 33

Characteristics of DHP block?

Answer 33

No frequency dependence | Marked tonic block

Question 34

What effects does DHP have on vascular system (3)?

Answer 34

Decrease in peripheral resistance Decreased after load Little effect on HR or contraction

Question 35

Drug listed in packet that has the least vascular specificity?

Answer 35

Nifedipine

Question 36

Drug used in cases of sub arachnoid hemorrhage to prevent neuropathy?

Answer 36

Nimodipine

Question 37

Secondary result of DHPs on the heart?

Answer 37

Reflex tachycardia except for amlodipine

Question 38

How do DHPs reduce angina?

Answer 38

They lower the oxygen demand of the heart

Question 39

Which DHP does depress cardiac function?

Answer 39

Nifedipine

Question 40

Why is Amlodipine the most commonly prescribed calcium channel blocker?

Answer 40

It has slow onset and long duration of action

Question 41

Phenylalkylamine (PAAs) cause what?

Answer 41

Vasodilation, less potent than DHP

Question 42

Effect of PAA on SA and AV node?

Answer 42

Slows conduction through SA and AV node to reduce heart rate and force of contraction

Question 43

How severe is the reflex tachycardia from PAA?

Answer 43

Blunted

Question 44

Characteristics of PAA block?

Answer 44

Marked frequency dependence | Very little tonic block

Question 45

Benzothiazepine affects the heart how?

Answer 45

Vasodilation, slows conduction, reflex tachycardia, but inhibits less than verapamil but more than DHPs

Question 46

Characteristics of BZP block?

Answer 46

Some tonic block | Some frequency block

Question 47

Of the three types of drugs discussed which affects heart rate the most?

Answer 47

Verapamil

Question 48

Of the three types of drugs discussed which affects AV conductance/Myocardial contraction the most?

Answer 48

Verapamil

Question 49

Of the three drugs listed which affects arterial vasodilation the most?

Answer 49

DHPs

Question 50

Most important side effects of calcium channel blockers?

Answer 50

Ankle edema Constipation Facial flushing Tachycardia

Question 51

Which class of drug causes the most constipation?

Answer 51

Verapamil

Question 52

Which class of drug causes the most facial flush/

Answer 52

DHPs

Question 53

Which class of drugs causes the most tachycardia?

Answer 53

DHPs

Question 54

Danger surrounding prompt release nifedipine?

Answer 54

Increased risk of subsequent heart attack due to reflex sympathetic response tachycardia