3.1.3 CCBs Flashcards
What calcium channels are blocked with CCBs?
L-type calcium channels-
Voltaged operated calcium channels that allow influx of Ca2+ into cells
Where are L-type VOCCs found?
Throughout body especially in
Vascular smooth muscle
Cardiac myocytes
SA and AV nodes
What do CCBs target?
Calcium initiated smooth muscle contraction
What are the 3 different classes of CCBs?
Dihydropyridines
Non-dihydropyridines:
-Phenylalkylamines
-Benzothiazapines
Each interact with different sites on a1 subunit, different selectivity for vascular smooth muscle or myocardium
What are dihydropyridines selective for?
Peripheral vasculature
Little chronotropic or inotropic effects
Cerebral vs peripheral selectivity, dictates which are given for hypertension
What do phenylalkylamines do?
Depresses SA node and slows AV conduction
Negavity inotropy
What do benzothiazapines do?
Sit in the middle, has effects on both heart and smooth muscle
When are CCBs the primary choice?
If patients have low renin
Give 3 examples of dihydropyridines
Amlodipine
Nifedipine
Nimodipine
-ipine suffix
Amlodipine half life vs other dihydropyridines
Has long half life, others tend to be shorter
When is nimodipine used?
Selective for cerebral vasculature, useful for ischaemic effects of subarachnoid haemorrhage
What are some adverse effects of dihydropyridines?
Ankle swelling
Flushing
Headaches (vasodilation)
Palpitations (compensatory tachycardia)
When can you not give dihydropyridines?
Unstable angina
Severe aortic stenosis
What are some drug interactions of dihydropyridines?
Amlodipine + simvastatin =
Increases effects of statins
What are phenylalkylamines?
Class IV anti-arrhythmic agent, prolongs AP/effective refractory period
Less peripheral vasodilatation, negative chronotropic and inotropic effects
