Calcium Channel Blockers Flashcards
During contraction of muscle Ca levels increase or decrease intracellularly?
Increase, once the contracion is over Ca returns to the sarcoplasmic Reticulium
What are the 6 types of Ca Channels?
L N P Q R T
Type L 5 sub units?
Alpha 1( main pathway) Alpha 2 Beta Gama Delta
3 types of Calcium Channel Blockers
Phenylalkylamines Benzothazepines DHP’s (1,4-Dihydropyridines)
Verapamil is a ?
Phenylalkylamines
Nifedipine is a ?
DHP’s (1,4-Dihydropyridines)
Diltiazem is a ?
Benzothazepines
Nicardipine is a ?
DHP’s (1,4-Dihydropyridines)
Amlodipine is a ?
DHP’s (1,4-Dihydropyridines)
NON DHP’s (1,4-Dihydropyridines) Diltiazem and Verapamil cause
Negative inotropic, chronotopic and dromotropic effect and a Positive lusitropic effect (Relaxation effect)
Ca Blockers decreased Perif vascualr Resistance by ?
Arteriole dilation, do not effect venous tone
Ca Blockers cause?
Decrease coronary vascular resistance, and increase coronary blood flow
KNOW THIS CHART
Beta Blockers can be used with which Ca Blockers?
DHP’s
Common Uses for Ca Blockers
Angina (vasospastic or exertional)
Unstable Angina
PSVT
HTN
Hypertrophic cardiomyopathy
Subarachnoid Hemorrhage ( Nimodipine)
Common Side Effects of Ca Blockers
Orthostatic HTN
Bradycardia
perif. edema
Dizziness
HA
Flushing and N/V
Increased AV Block can occur with Beta Blocker and Ca channel blocker concomitent use unless which Ca blocker catagory is used?
DHP’s
Name 3 DHP’s
Nifedipine, Nicardipine, Nimodipine
DHP’s cause the following hemodynamically?
Drop in BP
increase in HR (baroreceptor response)
Increased contractility
increase in CO
Phenylalkylamines Name them
Verapamil is the only one
Caution using Verapamil in patients using?
Beta Blockers and Digoxin
CONTRAINDICATIONS
of
Verapamil
WPW
Sick sinus syndrome
AV block
Heart Failure
Verapamil Dose
Initial dose: 5 to 10 mg IV bolus over at least 2 minutes
Repeat dose: 10 mg, 30 minutes after the first dose if the initial response is not adequate
Diltiazem Dose
initially 0.25 mg/kg over 2 min. If inadequate give 0.35 mg/kg over 2 min-15 min after 1st dose.
Nifedipine Dose
Extended release tablets: 30 to 60 mg orally once a day
Immediate release capsules: 10 mg orally 3 times a day
Nicardipine Dose
Initial dose: 5 mg/hour by IV infusion
may be increased by 2.5 mg/hour every 5 minutes to a max dose of 15 mg/hour, until desired blood pressure reduction is achieved.
Amlodipine Dose
2.5 - 10 mg PO QD
Nimodipine Dose
IV : For the first two hours of treatment 1 mg/5ml/hr of nimodipine IV
After 2 hours to 2 mg/10ml/hr provided no severe decrease in blood pressure is observed
