Chapter 48 Pharm

aka calcium antagonists
drugs that prevent calcium ions from entering cells
used to treat HTN, angina pectoris and cardiac dysrhythmias

calcium channels blocked = vasodilation
two groups = non-dihydropyridines (arterioles and heart) and dihydropyridines (act on arterioles)

block calcium channels by effects on heart and blood vessels
reduces arterial pressure
increases coronary perfusion
reduces heart rate
decreases AV nodal conduction
decreases force of contraction
causes vasodilation accompanied with ^

class: non-dihydrophyridine
use: angina pectoris, essential HTN, cardiac dysrhytmias
adverse: constipation (can be decreased by increasing dietary fiber and fluids) and dizziness
nursing imp: don't want to give to people who already have heart block because can cause heart block
IV verapamil can cause serious CV effects, BP and ECG should be monitored with resuscitation equipment immediately available
PO- ER 120-180mg/day, IR 40-120mg/day

severe hypotension
bradycardia and AV block
ventricular tachydysrhythmias

class: non-dihydropyridine
blocks calcium channels
use: angina pectoris, HTN, cardiac dysrhytmias
adverse: bradycardia, sick sinus syndrome, heart failure, second or third degree heart block
nursing imp: less constipation

lowered blood pressure
increased heart rate
increased contractile force
cannot be used to treat dysrhythmias
likely to cause reflex tachycardia

use: angina pectoris, HTN
adverse: reflex tachycardia - increased cardiac O2 demand can increase pain for anginal patients
nurisng imp: can be combined with a beta blocker for prevention of reflex tachycardia