Antihypertensive drugs Flashcards
What are the blood vessels that produce the most resistance to blood flow?
The arterioles
What kind of effects does the autonomic nervous system deal with?
Very short term
What drugs can be used to reduce cardiac output?
Beta adrenergic blockers (not ideal)
Calcium channel blockers
What kind of drugs are used to dilate resistance vessels?
Calcium channel blockers
Renin-angiotensin system blockers
Alpha 1 adrenoceptor blockers
Nitrates
What kind of drugs can be used to reduce vascular volume?
Diuretics
RAS blockers
Where is angiotensin converting enzyme located?
Richest in the lungs (endothelial cells of the vasculature)
What is the receptor for Angiotensin II on blood vessels called?
AT(1) receptor
How does AtII act on blood volume?
Adrenal cortex of the medulla contain receptors for AtII which stimulate production of aldosterone.
How many amino acids is AtII made up of? What does this mean?
8, which means inhibiting its receptor with a drug shouldn’t be too hard
What are some common ACE inhbitors?
Perindopril
Ramipril
Anything else ending with -pril
What are ARBs?
Angiotensin Receptor Blockers
What are some ARB’s?
Candesartan
Irbesartan
Anything else ending in -sartan
What are the uses of beta adrenoceptor blockers?
Antiarrhythmic
Decreasing BP by decreasing HR
Heart failure
Angina (decreasing effort done by the heart)
Where are the alpha1 receptors most commonly located?
Arterioles (they act here as vasoconstrictors)
What is the use of alpha1 adrenoceptor blockers?
They can reduce blood pressure by reducing the work that the heart does by dilating arterioles and in turn reducing TPR/PVR and thus reducing BP
Name an alpha1 adrenoceptor blocker:
Prazosin (currently the only one in use)
How do calcium channel blockers work?
They reduce myocardial membrane depolarization
signalling
Important role in actin-myosin interaction
Fun fact
The sodium / calcium exchanger on cardiomyocytes is so efficient that it can maintain an intracellular calcium concentration that is 25 fold lower than the extracellular environment.
What do calcium channel blockers do in cells that they act on?
They reduce the rate of time calcium ions enter the cardiomyocytes making it take slightly longer and thus reducing heart rate.
What are the types of calcium channel blockers?
Cardioselective channels
Vascular smooth muscle selective
What are the names of calcium channel blockers that act on vascular smooth muscle?
Dihydropyridines; examples of these are:
Nifedipine
Amlodipine
typically these drugs end with dipine
What do cardioselective calcium channel blockers do?
Reduce cardiac contractility
Reduce cardiac automaticity
Name a cardioselective calcium channel blocker
Verapamil
What drug family acts on both peripheral vascular tissue and the heart?
Diltiazem
