Question | Answer |
CCB have their greatest effects on: | the heart and blood vessels |
What are CCBs used to treat? | - hypertension
- Angina pectoris
- cardiac dysrhythmias |
Critical Role that CCB play? | - function of vascular smooth muscle (VSM) |
CCBS act selectively on? | - peripheral arterioles and arteries
- no effect on veins |
Nifedipine | - works on arterioles |
verapamil & diltiazem | - works on arterioles AND heart |
Verapamil | - blocks ca channel in blood vessels and in the hearts |
Verapamil uses: | - angina (widely used)
- essential hypertension (2nd line agent after Thiazide diuretics)
- cardiac dysrhythmias (given IV) |
5 direct effects of Verapamil: | 1. Decrease of AV nodal conduction (most important**)
2. blockade at peripheral arterioles causing dilation and reducing arterial pressure
3. Block at arterioles and arteries of heart to increase coronary perfusion
4 & 5 |
Indirect (reflex) effect of Verapamil | - lowers blood pressure which activates baroreceptor reflex |
Does Verapamil have net effect on the heart? | NO |
Verapamil administration | - given orally or IV |
Verapamil ADVERSE EFFECTS | - CONSTIPATION ** Most common
- bradycardia
- Gingival hyperplasia
- Chronic eczematous rash |
Verapamil food and drug interactions | - Digoxin
- Beta Blockers
- Grapefruit Juice |
What is used to remove Verapamil from the GI tract in toxicity? | - gastric lavage followed by activated charcoal |
DILTIAZEM | - Blocks ca channels in heart and vessels like Verapamil
- used for angina, essential hypertension, cardiac dysrhythmias |
DILTIAZEM side effects: | - less constipation than Verapamil
most common:
- dizziness
- flushing
- headache
- edema of ankles and feet
-Chronic eczematous rash |
DILTIAZEM food and drug interaction | - beta blockers
- digoxin
- grapefruit juice |
NIFEDIPINE | - Works on arterioles but NOT the heart |
Indirect effects of NIFEDIPINE | - Activated baroreceptor reflex
(reflex occurs mainly with IMMEDIATE-RELEASE formulation of Nifedipine) |
SAFETY ALERT NIFEDIPINE** | - Immediate release has been associated with increased mortality in patients with MI & unstable angina |
NET EFFECTS OF NIFEDIPINE | 1. lowers BP
2. Increases HR
3. Increases contractile force |
NIFEDIPINE uses: | - Angina
- Hypertension
- Suppress preterm labor |
NIFEDIPINE adverse effects: | - Reflex tachycardia**:combine with beta blocker to prevent
- flushing, dizziness, headache, peripheral edema, gingival hyperplasia |
NIFEDIPINE drug interactions | - Beta blockers (although used for relex tachycardia)
- Toxicity can occur |