Lectures 10 and 11: Hypertension Flashcards
Define hypertension.
Persistently higher than normal blood pressure
When should hypertension be treated?
When mean BP > 150/95mmHg
What is the equation for BP?
BP = CO x TPR
What is the equation for CO?
CO = SV x HR
What regulates SV?
Ventricles
What regulates the HR?
SA node
Where are baroreceptors found?
Kidneys, carotid arteries, arch of aorta
What signals are received by medulla?
Vagus and glossopharengeal
What receptors in the heart does the sympathetic system act on?
beta1
Increases cAMP and calcium to increase rate and force of contraction
What receptors in the heart does the parasympathetic system act on?
M2 receptors
Decrease cAMP levels
What receptors in the periphery does the sympathetic system act on?
NA –> alpha 1 –> IP3 –> Ca2+ –> constriction
A –> beta 2 –> cAMP –> relaxation
What effects does Ang2 have?
Increases sympathetic activity
Increases salt and water retention
Increases aldosterone
Increases ADH
Arteriolar vasoconstriction
What is AT1R the receptor for?
Angiotensin 2
How does aldosterone work?
Binds cytoplasmic receptors which binds to the nucleus to increase expression of Na channels
What would be the drug of choice for someone under the age of 55 suffering from hypertension?
ACE inhibitor or angiotensin receptor blocker
What would be the drug of choice for someone over the age of 55 suffering from hypertension?
Calcium channel blocker
What would be the drug of choice for a Black African/American suffering from hypertension?
Calcium channel blocker
What are the 5 classes of anti-hypertensives?
ACE inhibitors and angiotensin receptor blockers
Calcium channel blockers
Diuretics
Beta blockers
Vasodilators
What are the side effects of ACE inhibitors?
Dry cough
1st dose hypotension
Renal impairment
Hyperkalaemia
What kind of drug is ramipril?
ACE inhibitor
Name an ACE inhibitor.
Ramipril
What kind of drug is losartan?
Angiotensin receptor blocker (ARB)
Name an ARB.
Losartan
What kind of drug is Spironolactone?
Aldosterone antagonist
What kind of drug is amlodipine?
Dihydropyridine (CCB)
Name a dihydropyridine.
Amlodipine
Name a phenylalkylamine.
Verapamil
Name a benzothiazepine.
Diltiazem
What are the three main classes of calcium channel antagonist?
Dihydropyridines
Phenylalkylamines
Benzothiazepines
What kind of drug is verapamil?
Phenylalkylamine (CCB)
What kind of drug is Diltiazem?
Benzothiazepine (CCB)
What are the side effects of CCBs?
Peripheral oedema
Flushing and headaches
What protein metabolises CCBs in the liver?
CYP3A4
What kind of drug is indapamide?
Thiazide (thiazide-like) diuretic
How does indapamide work as a diuretic?
Opens kATP allowing K to flow out of cell - hyperpolarises smooth muscle cells - Ca channels never activated to open -relaxation/dilation of the arteriole
Name a thiazide (thiazide-like) diuretic.
Indapamide
What are the side effects of diuretics?
Hypokalaemia
Increased urate
Increased glucose
Increased blood lipids
What condition may make diuretics contraindicated?
Diabetes
What are the side effects of beta blockers?
Fatigue
Vaso/bronchoconstriction
Hypoglycaemia
Name a selective b1 antagonist.
Bisprolol
Name a non-selective (B1 and B2) beta blocker.
Propranolol
Name a vasodilator.
Doxazosin
