Calcium Channel Blockers Flashcards Preview

3: Drugs for Clinical Medicine > Calcium Channel Blockers > Flashcards

Flashcards in Calcium Channel Blockers Deck (27)
Loading flashcards...
1
Q

Give 3 examples of non-rate limiting CCBs?

A
  • Amlodipine
  • Felodipine
  • Nifedipine

(they all end in -dipine)

2
Q

What are non-rate limiting CCBs known as?

A

Dihydropyridine CCBs

3
Q

Give 2 examples of rate-limiting CCBs?

A
  • Verapamil

- Diltiazem

4
Q

What is important to note when prescribing diltiazem?

A

Should be prescribed by brand

5
Q

What is the mechanism of action of CCBs?

A

They inhibit the influx of calcium ions into vascular smooth muscle, therefore decreasing intracellular calcium, which reduces contractility, conductivity, and oxygen demand of the heart

6
Q

What are the routes of delivery of CCBs?

A
  • PO

- IV

7
Q

What CCBs can be given IV?

A
  • Verapamil

- Nicardipine

8
Q

Why are some CCBs available in a MR preparation?

A

As some have short half lives

9
Q

What are the indications for non-rate limiting CCBs?

A
  • Prophylaxis in stable angina

- Hypertension

10
Q

When are CCBs first line in hypertension?

A

In those who are >55 or Afro-Caribbean

11
Q

Why are CCBs first line in Afro-Caribbean?

A

As low-renin hypertension for which CCBs are effective is common in this ethnic group

12
Q

What are the indications for rate-limiting CCBs?

A
  • SVT
  • Prophylaxis and treatment of angina
  • Hypertension
13
Q

What can diltiazem cream be used for?

A

Haemorrhoids

14
Q

What are the cautions/contraindications for CCBs?

A
  • Unstable angina
  • Severe aortic stenosis
  • Recent MI (within 1 month)
15
Q

What might CCBs interact with?

A
  • Other anti-hypertensives
  • Digoxin
  • Theophylline
  • Anti-epileptics
16
Q

What might happen if CCBs are given with digoxin?

A

Increased plasma digoxin concentration

17
Q

What might happen if CCBs are given with theophylline?

A

Increased plasma theophylline concentration

18
Q

What might happen if CCBs are given with anti-epileptic drugs?

A

Reduced effect of dihydropyridine CCBs

19
Q

What are the common side effects of CCBs?

A
  • Headache
  • Flushing
  • Abdominal pain
  • Hypotension
  • Tachycardia
  • Fatigue
  • Peripheral oedema
  • Cold peripheries
20
Q

What are the less common side effects of CCBs?

A
  • Bradycardia, heart block and heart failure in patients with poor LV function
  • Impotence
21
Q

What CCB causes impotence?

A

Felodipine

22
Q

What might happen to the side effects of flushing, hypotension, dizziness, and ankle swelling with CCBs?

A

May settle down after couple of weeks then resolve

23
Q

What patient counselling is required with CCBs?

A
  • Lifestyle measures
  • Food interactions
  • Compliance in angina
24
Q

What should be discussed regarding lifestyle measures with CCBS?

A

Discuss reduction of other cardiovascular risk factors

25
Q

What should be discussed regarding food interactions with CCBs?

A

Do not consume grapefruit or its juice as this may interact

26
Q

Why should people not consume grapefruit with CCBs?

A

Grapefruit inhibits the CYP3A4 system, which increases the bioavailability of the calcium channel blocker and potentiates its anti-hypertensive effect

27
Q

What should be discussed regarding compliance with CCBs in angina?

A

If you have angina and stop taking CCB, may worsen