CCB Flashcards
Nifedipine
Nifedipine
Dihydropyridine CCB
Non competitively binds to alpha sub unit of L type VGCC, prevents the influx of calcium. Leads to preferential dilation of peripheral and coronary arteries. Has minimal action at veins and minimal action at SA/AV node.
Leads to coronary vasodilation, decrease BP, decrease SVR, decrease afterload. primary site of action: peripherla arterioles.
Pk:
onset: immediate - IV
e1/2t: 3-7 hours
pB: 90%
liver metabolism with 70% excreted in urine.
SE:
Hypotension - may lead to reflex tachycardia, is often perscribed with BB
flushing/HA/vertigo
constipation / parathesia
potentiates NMB
Peripheral lower limb edema
C/I:
hypotension
severe aortic stenosis
can increase r/f LA toxicity r/t Na+ and Ca++ block
Dantrolene
INCREASES R/F DIGOXIN TOXICITY
caution with BB but can be perscribed with nifedipine
Verapamil
Verapamil
Non dihydropyridine CCB
Non competiviely binds to alpha subunit at L type VGCC, blocks the slow influx of calcium. Prefentially binds to AV/SA node. Leads to decrease in HR, contractility, AV conduction. Minimal dilating effects at peripheral arterioles and coronary arteries - most potent at AV/SA
Used for supraventricular tachycarrthmias (SVT, AFIB, AFlutters), HTN, reduce afterload, hypertrophic cardimyopathy and for prinzmetal’s angina.
Pk:
onset: rapid
e1/2t; 6-8 hours
PB: 90%
metabolized by liver to actie metabolite norverapamil, excreted 70% in urine.
dose:
2.5 - 10 mg IV over 1-3 minutes
max dose: 20 mg
SE:
Bradycardia
hypotension
myocardial depression
nausea/constipation
potentiates NMB
gingival hyerplasia
C/I:
Av block
sick sinus syndrome
WPW syndrome
avoid with beta blockers
dantrolene
will increase r/f digoxin toxicity
can increase r/f LA toxicity r/t Na+ and Ca++ block
increase myocardial depression with volatiles
Diltiazem
Diltiazem
Non dihydropyridine CCB - INTERMEDIATE CCB
class 4 anti-arrthymic
MOA:
Binds to alpha subunit of L type VGCC blocks the slow influx of calcium into the myocardium, works preferentially at the AV/SA node. Decreases HR, decreases contractility, has intermediate affects at peripehral arterioles. Decreases SVR, BP, afterload.
Used in supraventricular tachyarrthymias (a.fib, aflutter, SVT)
Pk:
onset: immediate
e1/2t: 4-6 hours
pB: 70-80%
Goes under extensive liver metabolism, excreted 30% unchanged in urine.
May need to decrease dose in liver disease.
dose:
5-20 mg IV over 2 minutes
gtt: 10 mg/hr
SE:
Bradycardia
hypotension
myocardial depression
potentiates NMB
nausea/constipation
C/I:
HB/HF
avoid with beta blockers
bradycardia, AV block
myocardial depressoin with volatiles
dantrolene
increase r/f digoxin
sick sinus syndrmome
acute MI or CHF
