Chapter 48: Calcium Channel Blockers

Question 1

calcium channel blockers have the greatest impact on

Answer 1

heart and blood vessels

Question 2

calcium channel blockers are used to treat

Answer 2

hypertension, angina pectoris, and cardiac dysrhythmias

Question 3

calcium channel blockers are also known as

Answer 3

• calcium antagonists
• slow channel blockers

Question 4

calcium channels open =

Answer 4

contractile process

Question 5

calcium channels blocked =

Answer 5

vasodilation

Question 6

consequences of therapeutic doses

Answer 6

selectively act on peripheral arterioles and arterioles of the heart (no significant effect in veins)

Question 7

consequences of calcium channel blockers on the heart

Answer 7

• myocardium (-/+ inotropic effect)
• SA node (pacemarker, reduce heart rate)
• AV node (decrease conduction velocity)

Question 8

calcium channel blockers act like

Answer 8

beta blockers

Question 9

classifications of calcium channel blockers

Answer 9

• Dihydropyrides
• Phenylalanine
• Benzothiazepine

Question 10

Dihydropyridines example

Answer 10

Nifedipine

Question 11

Dihydropyridines act primarily on

Answer 11

arterioles

Question 12

Phenylalanine example

Answer 12

Verapamil

Question 13

Verapamil acts on

Answer 13

arterioles and directly on the heart and blood vessels

Question 14

Benzothiazepine example

Answer 14

Diltiazem

Question 15

Diltiazem act on

Answer 15

arterioles and directly on the hear and blood vessels

Question 16

Verapamil and Diltiazem effects

Answer 16

Hemodynamic effects

Question 17

what are the 5 Hemodynamic Effects

Answer 17

• Blockade at peripheral arterioles (reduces arterial pressure)
• blockade at arteries and arterioles of heart (increases coronary perfusion)
• blockade at SA node (reduces heart rate)
• blockade at AV node (decreases AV nodal conduction)
• Blockade in the myocardium (decreases force of contraction)

Question 18

what is the most important hemodynamic effect

Answer 18

Blockade at AV node

Question 19

Verapamil [Isoptin] therapeutic uses

Answer 19

• angina pectoris (vasospastic and exertional angina)
• essential hypertension (second line agent)
• Cardiac dysrhythmias (atrial flutter, atrial fibrillation, paroxysmal supraventricular tachycardia (IV)
• headaches

Question 20

verapamil [Isoptin] is

Answer 20

highly protein bound
- 1st pass metabolism

Question 21

verapamil [Isoptin] adverse effect s

Answer 21

• constipation **
• Dizziness
• facial flushing
• headache
• edema of ankles and feet
• Gingival hyperplasia
• heart block

Question 22

Verapamil [Isoptin] food interaction

Answer 22

Grapefruit juice

Question 23

Verapamil [Isoptin] toxcitiy

Answer 23

• severe hypertension
• bradycardia and AV block
• ventricular tachydysrhythmias

Question 24

Diltiazem [Cardizem, Tiazac] benefits

Answer 24

• similar to verapamil except less constipation

Question 25

Diltiazem [Cardizem, Tiazac] administration

Answer 25

oral preperations often sustained release formulas

Question 26

Diltiazem [Cardizem, Tiazac] is used for

Answer 26

hypertension, angina, and cardiac dysrhythmias

Question 27

Nifedipine cannot be used to treat

Answer 27

dysrhythmias

Question 28

Nifedipine is less likely than verapamil to exacerbate

Answer 28

preexsiting cardiac disorders

Question 29

Nifedipine [Adalat, Adalat XL] theapeutic uses

Answer 29

- angina pectoris - hypertension - investigational basis: relieve migraine headaches

Question 30

Nifedipine [Adalat, Adalat XL] direct effects

Answer 30

- limited to blockade of Ca channels in vascular smooth muscle

Question 31

Nifedipine [Adalat, Adalat XL] has no direct suppressant effect on

Answer 31

automaticity, AV conduction, or contractile forces

Question 32

Nifedipine [Adalat, Adalat XL] indirect effects

Answer 32

lowered blood pressure (BP) activates baroreceptor reflex (primarily with immediate release versus sustained release)

Question 33

Nifedipine effects

Answer 33

- lowered blood pressure - increased heart rate - increased contractile force

Question 34

Nifedipine adverse effects

Answer 34

- flushing - dizziness, headache - peripheral edema - gingival hyperplasia - chronic eczematous rash (older patients) - increases cardiac oxygen demand

Question 35

Nifedipine can be combined with _____ for prevention of __________

Answer 35

beta blocker reflex tachycardia

Question 36

Nifedipine adverse effects

Answer 36

- increased mortaliy in patients with MI and unstable angina

Question 37

Nursing implications for Nifedipine

Answer 37

- monitor BP, rhythm, HR - many are sustained release (do not crush) - monitor for constipation, peripheral edema, cardiosupression