Calcium Channel Blockers Flashcards
Calcium channel blockers are for
Hypertension, blocks calcium channels
- muscles need calcium to rush in & open up stored calcium to cause muscle constriction/contraction
CCB do what
Block influx of calcium that triggers muscle contraction
CCB cause what to relax
Smooth muscle in blood vessels (vasodilation)
How does CCB affect cardiac muscle
Alters ability of the muscle to transmit electrical impulses
What do SOME CCB work on
The SA & AV node of the heart
What do ALL CCB work on
Vascular smooth muscle
What do SOME CCB work directly on
The heart to slow HR
Dihydropyridines (DHP’s)
ONLY on blood vessels
Non-DHP’s
directly affect heart SA & AV nodes (can cause many drug interactions)
Two non-DHP’s
Diltiazem & verapamil (both metabolized in liver)
DHP or non-DHP causes decrease in AV & SA node conduction
Non-DHP’s
DHP or non-DHP causes decrease in HR
Non-DHP’s
Do DHP’s affect AV & SA nodes?
NO
Do DHP’s affect HR?
NO, but maybe slightly since vasodilation can cause HR to increase when changing positions
What causes the most vasodilation in peripherial and coronary?
DHP’s
Do Non-DHP’s cause vasodilation in peripherial and coronary?
yes
Which one causes slightly more vasodilation in peripheral and coronary? verapamil or diltiazem
diltiazem
How do Non-DHP’s and DHP affect vasodilation in cerebral?
They increase vasodialtion in cerebral by the same amount
What side effects from excessive vasodilation?
Headache and flushing
What is a bigger issue in causing headache and flushing? Non-DHP or DHP?
DHP’s
Side affects in both Non-DHP and DHP
Hypotension, headache, and flushing
Other side affects in DHP’s
Reflex tachycardia and edema
Other side affects in Non-DHP’s
Constipation, bradycardia, AV block, and CHF
Reflex tachycardia
DHP do not affect HR but they do affect vessels and can lower pressure so much that the blood can rush to lower extremities and HR can compensate for low BP.
INDIRECT AFFECT
would we use DHP for a fib or tachy
NO
DHP’s have no effect on the heart rate
