Calcium Channel Blockers

Question 1

Effects

Answer 1

1) vasodilators of smooth muscle by inhibition of transmembrane flux of calcium ions into smooth muscle cells
2) myocardial depressants by inhibiting calcium movement into cardiac muscle cells–dec contractility, HR, AV conduction
- avoid in HF, AV block, cardiogenic shock, low CO

Question 2

Uses

Answer 2

• HTN
• ischemia–cerebral and coronary
• arrhythmia–SVT

Question 3

Verapamil

Answer 3

• slows rate of spontaneous phase 4 depolarization in SA and AV nodes
• second line for SVT
• lowers BP, lowers HR
• hepatic metabolism

Question 4

verapamil: negative inotrope effects

Answer 4

• potientiated by BAD drugs
• Beta blockers
• Anesthetics (volatile)
• Digitalis and Dantrolene
• as effective as digitalis in slowing ventricular response in presence of afib or flutter, but more rapid onset

Question 5

nifedipine

Answer 5

-treats HTN

Question 6

nicardipine

Answer 6

• relaxation of coronary vascular smooth muscle at drug levels that cause little or no neg inotropic effects
• decreases SVR most in hypertensive pts
• no coronary steal
• effective in chronic stable angina and HTN

Question 7

nicardipine: metabolism

Answer 7

-highly protein bound, metabolized by liver, almost completely absorbed after po admin

Question 8

nicardipine: side effects

Answer 8

-flushing, HA, pedal edema