Anti-hypertensives Flashcards
How do ACE inhibitors work?
ACE inhibitors are Angiotensin Converting Enzyme antagonists
This prevents the conversion of Angiotensin I to Angiotensin II
What are the effects of ACE inhibitors?
They prevent vasoconstriction and decreases the retention of Na+ and Water, therefore decreasing blood volume
What are some examples of ACE inhibitors?
Lisinopril
Enalopril
Perindopril
Ramipril
What is a side effect of ACE inhibitors?
They can cause a dry cough due to increased bradykinin secretion
Who are ACE inhibitors used on?
They are used in the first line treatment in hypertension with Type II diabetes
They are also used in hypertension of those under the age of 55 who are NOT Black African or Afro-Carribean
They are also used in heart failure as they decrease vasomotor tone, blood volume and blood pressure
How do Angiotensin II Receptor Blockers work?
These block receptors in the body to angiotensin II
This prevents the effects of angiotensin II
This prevents vasoconstriction, Na+ and water retention
What are some examples of Angiotensin II Receptor Blockers (ARBs)?
Losartan
Irbesartan
Candesartan
Valsartan
Who are Angiotensin II Receptor Blockers used on?
They are used in the treatment of hypertension and heart failure in those who cannot tolerate ACE inhibitors
They can be used in those with type II diabetes and those under 55 who are NOT Black African or Afro-Carribean
What are loop diuretics used for?
They are useful in the treatment of congestive heart failure
This is because they decrease blood volume and this decrease strain on the heart
They are also useful in decreasing peripheral and pulmonary oedema
What are some examples of loop diuretics?
Furosemide
Bumetanide
Which type of Ca2+ channel blocker is used as an anti-hypertensive?
DIhydropyridine Ca2+ blockers
What are some examples of Dihydropyridine Ca2+ blockers?
Amplodipine
Nicardipine
How do Dihydropyridine Ca2+ blockers work?
They work on smooth muscle in blood vessels, decreasing SVR and arterial blood pressure
This reduces the workload of the heart, making them useful in the treatment of hypertension, heart failure, angina and supra ventricular tachycardias
What are some examples of vasodilatory hypertensives?
Hydralazine
Minoxidil
What is a common side effect of minoxidil?
Hypertrichosis (Excessive hair growth)
What is hypertrichosis?
Excessive hair growth
What are some examples of α2 agonists?
Methyldopa
Clonidine
How do α2 adrenoceptor agonists work in hypertension?
They bind to and activate α2 adrenoceptors, which causes vasodilation
What are some examples of α1 adrenoceptor antagonists?
Prazosin
Terazosin
How do α1 adrenoceptors work?
They bind to and block α1 adrenoceptors which causes vasodilation
What is an example of a cardiac glycoside?
Digoxin
What is an example of a ß-adrenoceptor agonist?
Dobutamine
What are some examples of drug classes that act as positive inotropes (Increase force of contraction)?
Cardiac Glycosides
ß-adrenoceptor agonists
How do cardiac glycosides work?
They are synthesised from foxgloves (Digitalis purpurea)
This blocks the sodium potassium pump
This usually sets up the Na+ gradient required for the Na+/Ca2+ pump
Lack of this gradient causes a build up of Ca2+ in the sarcoplasmic reticulum
This increases the strength of contraction
What are the preferred treatment options for heart failure?
Don’t flog a dying horse - It is better to reduce the hearts workload than to make it work harder
ACE inhibitors, ARBs and diuretics are better
ß-blockers can also be used
What is angina?
Pain due to transient ischaemia, when O2 supply to the heart does not meet the needs of the heart
What are the 2 forms of angina?
Stable
Unstable
What is meant by stable angina?
Angina that is brought on by vigorous exercise
What is meant by unstable angina?
Angina that is brought on by simple activity or even at rest
What is the main symptom of angina?
Dull chest pain
What is the main treatment option used for angina?
Organi nitrates
How do organic nitrates work?
Organic nitrates bind with Thiols (-SH) in vascular smooth muscle
This releases nitric oxide
Nitric Oxide activates granulate cyclase
This increases levels of cGMP
This lowers intracellular Ca2+ levels
This causes relaxation of vascular smooth muscle
This decreases SVR
What are some examples of organic nitrates?
Glyceryl Trinitride (GTN) = Short acting
Isosorbide Di/Mono-Nitrate = Longer acting
What are the primary actions of Nitric Oxide?
Vasodilation lowers preload
This reduces workload of the heart
This decreases force of contraction by Starling mechanism
This decreases the hearts need for O2
What are the secondary actions of Nitric Oxide?
Action of coronary collateral arteries improves O2 delivery
It acts on veins most, arteries second then not on arterioles
