Calcium Channel Blockers

Question 1

Calcium channels are gated pores in the cytoplasmic membrane that regulate

Answer 1

calcium entry into cells

Question 2

in blood vessels, calcium entry causes _______________ and hence calcium channel blockage causes ________________

Answer 2

vasoconstriction; vasodilation

Question 3

In the heart, calcium entry _________ heart rate, AV conduction and myocardial contractility, so calcium channel blockade has the opposite effects

Answer 3

increases

calcium channel blockade causes decrease in HR, AV conduction, myocardial contractility

Question 4

in the heart, calcium channels are coupled to ____________ receptors, activation of which enhances calcium entry. As a result calcium channel blockade and __________ blockade have identical effects on cardiac function

Answer 4

beta1; beta

Question 5

At therapeutic doses, nifedipine and other dihydropyridines act primarily on vascular smooth muscle. In contrast, Verapamil and diltiazem act on ______________ and ___________

Answer 5

vascular smooth muscle; the heart

Question 6

All CCBs promote

Answer 6

vasodilation and hence are useful in hypertension and angina pectoris

Question 7

Because they suppress AV conduction, ________________ and _______________ are useful for treating cardiac dysrhythmias (in addition to hypertension and angina pectoris)

Answer 7

Verapamil; Diltiazem

Question 8

Because of their cardiosuppressant effects, Verapamil and Diltiazem can cause

Answer 8

bradycardia, partial or complete AV block and exacerbation of heart failure

Question 9

_________________ blockers intensify cardiosuppression caused by Verapamil and Diltiazem

Answer 9

Beta Blockers

Question 10

Nifedipine and other dihydropyridines can cause reflex _______________. It is most intense with immediate release formulations and much less intense with sustained release formulations

What can be used to suppress this reflex _____________ caused by Nifedipine and other dihydropyridines?

Answer 10

tachycardia

Beta blockers can be used

Question 11

Because they cause vasodilation, all CCBS can cause

Answer 11

dizziness, headache, peripheral edema

Question 12

In toxic doses, Nifedipine and other dihydropyridines can cause _________________, just like Verapamil and Diltiazem.

Answer 12

cardiosuppression

Question 13

Immediate release Nifedipine has been associated with increased mortality in patients with __________________. The National Heart, Lung, and blood institute recommends that immediate release Nifedipine, especially in higher doses, be used with ________________, if at all.

Answer 13

MI and unstable angina, although a causal relationship has not been established; great caution