Calcium Channel Blockers-MJ Flashcards

1
Q

What happens in the blood vessels when calcium channels are blocked?

A

Contraction will be prevented and vasodilation will result

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2
Q

What are the three areas in the heart that have calcium channels?

A

Myocardium, SA node, AV node

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3
Q

Calcium channels at all three sites in the heart are coupled to _____ receptors

A

Beta1 adrenergic receptors

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4
Q

Calcium flow in the myocardium increases force of contraction. If the calcium channels in the atrial and ventricular muscle are blocked, ______ will diminish.

A

Contractile force

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5
Q

What is the pacemaker (SA node) activity of the heart regulated by?

A

Calcium

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6
Q

When calcium channels are open in the SA node, spontaneous discharge of the SA node increases. What happens when we block the calcium channels?

A

Pacemaker activity declines resulting in reduced HR

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7
Q

Since impulses from the SA node must pass through the AV node on the way to the ventricles, regulation of AV conduction plays a critical role in ________.

A

Coordinating contraction of the ventricles with contraction of the atria

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8
Q

What is the excitability of AV nodal cells regulated by?

A

Calcium entry

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9
Q

In the AV node, when calcium channels are open, calcium entry increases and the cells of the AV node discharge more readily. What happens when we block those calcium channels?

A

Discharge of AV nodal cells is depressed so there is a decrease velocity of conduction through the AV node

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10
Q

What are the two areas where calcium channels are found?

A

Blood vessels and heart (myocardium, SA node, AV node)

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11
Q

What are the two types of calcium channel blockers?

A

Dihydropyridines and non-dihydropyridines

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12
Q

What calcium channels receptors do the dihydropyridines block?

A

Blood vessel ones ONLY

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13
Q

What calcium channel receptors do the non-dihydropyridines block?

A

BOTH the blood vessel and heart receptors!

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14
Q

What are the 3 drugs of the dihydropyridines?

A
  • Nifedipine XL
  • Amlodipine
  • Amlodipine/ Benazepril
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15
Q

What are the indications for giving a dihydropyridine medication?

A

Hypertension

Angina pectoris

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16
Q

What are the 2 non-dihydropyridines medications?

A

Verapamil

Diltiazem

17
Q

What are the indications for giving a non-dihydropyridine medication?

A

Hypertension

Angina pectoris

A-fib

18
Q

What are the adverse effects of ALL calcium channel blockers?

A
  • Dose dependent peripheral edema
  • Headache
  • Flushing
  • Dizziness
19
Q

If a patient who is on a CCB comes in and complains that his shoes don’t fit anymore, what adverse effect is that patient experiencing?

A

Dose dependent peripheral edema

20
Q

The dihydropyridines have an adverse effect that the non-dihydropyridines don’t have. What is that adverse effect?

A

Reflex tachycardia

21
Q

Even though other dihydropyridines can cause reflex tachycardia, it usually is only seen with what type of medication, which is ___?

A

Medications that are IR (immediate release); Nifedipine IR

22
Q

Is reflex tachycardia potentially dangerous. Why or why not?

A

Yes, it can lead to an MI

23
Q

If you are on a CCB that could cause reflex tachycardia, what other drug could you take to suppress the reflex tachycardia?

A

Beta blocker

24
Q

What are the 4 adverse effects seen with the non-dihydropyridines ONLY?

A
  • Bradycardia
  • CYP34A interactions
  • Constipation
  • Avoid with heart failure or blocks!!!
25
Q

Constipation is one of the adverse effects of the non-D drugs. Which drug primarily causes constipation?

A

Verapamil

26
Q

Why are diltiazem and verapamil (both non-D drugs) dangerous for clients with heart failure, sick sinus syndrome, or third-degree AV blocks?

A

These drugs have cardiosuppressant effects. Blockade of the calcium channels in the heart can compromise cardiac function

27
Q

Diltiazem and verapamil can be dangerous for clients with heart failure, sick sinus syndrome, or third-degree AV blocks because blockade of calcium channels in the heart compromises cardiac function. What happens to these patients when there is blockage of calcium to the SA node?

A

Bradycardia

28
Q

Diltiazem and verapamil can be dangerous for clients with heart failure, sick sinus syndrome, or third-degree AV blocks because blockade of calcium channels in the heart can compromise cardiac function. What happens to these patients when there is blockage to the AV node?

A

Partial or complete AV block

29
Q

Diltiazem and verapamil can be dangerous for clients with heart failure, sick sinus syndrome, or third-degree AV block because blockade of calcium channels in the heart can compromise cardiac function. What happens to patients when there is blockage in the myocardium?

A

Decrease contractility

30
Q

If the heart is healthy, the blockage to the SA node, AV node, or myocardium rarely will have clinical significance. But if you have heart failure, sick sinus syndrome, or third-degree AV block, diltiazem and verapamil can seriously excerbate dysfunction. These two drugs should be used with CAUTION in patients with _____. These two drugs MUST NOT BE USED in patients with ________.

A

Used with caution in patients with cardiac failure

Must not be used in patients with sick sinus syndrome, second-degree or third-degree AV block

31
Q

SA node is the pacemaker of the heart. It discharges and impulses spread rapidly throughout the ____ along the intermodal pathways. What does this rapid conduction allow?

A

Atria; allow the atria to contract in unison

32
Q

AV node: Impulses from the atria must pass through the AV node to reach the ___.

A

Ventricles

33
Q

AV node: In the healthy heart, impulses arriving at the AV node are delayed before going on to excite the ventricles. Is this delay normal? Why or why not?

A

Yes it is normal; it provides time for blood to fill the ventricles before ventricular contractions

34
Q

What are the function of the fibers of the His-Purkinje System?

A

Conduct electrical excitation very rapidly through all parts of the ventricles

35
Q

His-Purkinje System: Impulses leaving the ___ stimulate the His-Purkinje System.

A

AV node

36
Q

His-Purkinje System: Impulses conducted rapidly down bundle of His enter the right and left bundle branches and distribute to the branches of the Purkinje fibers. These impulses travel quickly so all regions of the ventricles are stimulated almost simultaneously. What does this all produce?

A

Synchronized ventricular contractions with resultant forceful ejection of blood