Flashcards in 9. Cardiovascular System Drugs Deck (8)
Class 1/ sodium channel blockers are used to prevent which condition?
After depolarisations as sodium channels in the open and inactivated state are blocked
Give an example of a class 1 drug
What do class 2 drugs do and how do they work?
Beta blockers (block beta 1 adrenoreceptors)
Decreases slope of pacemaker potential in SAN
Inhibits adenyl cyclase so negative inotropy
What are class 3 drugs and why are they not used?
They prolong the action potential by blocking K+ channels
(In theory stop after depolarisations by increasing absolute refractory period)
Actually can be pro-arrhythmic so not used
How do ACE inhibitors work?
Prevent formation of angiotensin II therefore causing dilation of arterioles and veins - decreases preload and after load
Angiotensin II also promotes aldosterone release - ACE inhibitors therefore reduce water retention hence decreased blood volume and preload on the heart
What is the primary function of organic nitrates in the treatment of angina?
Venodilation to decrease venous pressure hence decreasing preload on the heart
What is the secondary function of organic nitrates in the treatment of angina?
Acts on coronary arteries improving O2 delivery