CCBs Flashcards
MOA - general
- Blocks Ca from entering the muscle cells of heart and arteries
- Muscle relaxation = arteries widen
- Reduces pressure
Types of CCB
- RL - V,D
- Dihydropyridines - A, F, N
Dihydropyridines vs RL
- influence on vessels
- less on mycoardium
Effects of RL CCB
- Vasodilatory
- decrease myocardial contractility + HR
- Highly negative inotropic effects (weaken force of muscle contraction of the heart)
Which CCB should be avoided in HF
- RL
- Decrease myocardial contractility
- In HF, contractility is weakened already
Can you give
the dihydropyridine CCBs in heart failure?
- Avoid short acting (nifedipine)
- NICE CKS recommends Amlodipine (or Felodipine) in heart failure
- Safest: amlodipine
Which dihydropyridine
CCB is short-acting?
- Nifedipine
- This is why they are commonly prescribed as
Modified release preparations - Since they are short-acting, they MUST be avoided in heart failure
Which dihydropyridine CCBs are long-acting?
Amlodipine
Felodipine
Verapamil + BB
Avoid - brady + cardiodepression
Verapamil - common SE
Constipation
Which has a better negative inotropic effect, Verapamil or diltiazem?
Verapamil
more likely to cause significant myocardial depression
Can Diltiazem be taken with Beta-blockers?
- Caution + specialist
- Although it has a negative inotropic effect (so there is a risk of bradycardia), the effects are not as great as Verapamil
Dihydropyridines - SE
- **Ankle swelling/oedema **
- Headache
- flushing
Does the oedema side effect of the
dihydropyridine CCBs
respond to diuretics?
- They only respond partially to diuretics
Ankle swelling switch to
- alternative CCB
- from Amlodipine to Felodipine) if they complain about ankle swelling
Dihydropyridines + BB
Yes
Special warning for
CCBs
- AVOID ABRUPT WITHDRAWAL (May precipitate myocardial ischaemia)
- Avoid Grapefruit juice as it prevents clearance of CCBs (mild study)
What are some interactions with CCBs?
- Statins
- Dabigatran + verapamil
- Carbamazepine
- BB + verapamil
- Grapefruit
- Macrolides (V, D)
What strength of MR
Diltiazem should be prescribed by brand?
more than 60mg MODIFIED RELEASE tablets or capsules
So e.g. Tildiem 90, Tildiem 120
you don’t need to specify brand for immediate release
Which CCBs must be prescribed by brand?
- Diltiazem MR tablets strength of more than 60mg
- Nifedipine MR - any strength
- This is because different modified release preparations don’t have the same clinical effect
