Hypertension & Heart Failure Flashcards
What are some examples of ACE inhibitors?
Ramipril
Captopril
Lisinopril
How do ACE inhibitors exert their actions?
Inhibit ACE therefore preventing conversion of Angiotensin I to Angiotensin II
What are the effects of ACE inhibitors?
Reduction in blood pressure
Vasodilation
Reduction in aldosterone release
Reduction in ADH release
Reduced cell growth and proliferation
What is the effect of ACE inhibitors on bradykinin?
Prevents breakdown
Build up of bradykinin => vasodilation via NO
What are some side effects of ACE inhibitors?
Persistent dry cough (bradykinin build up)
Angioedema
Renal failure
Hyperkalaemia
What are some examples of Angiotensin II receptor blockers?
Losartan
Candesartan
Eprosartan
How do ARBs exert their effects?
Block AT1 receptors
Inhibit Ang-II mediated vasoconstriction
What are some side effects of ARBs?
Renal failure
Hyperkalaemia
What are different classes of calcium channel blockers?
Dihydropyridine
Non-dihydropyridine
How do dihydropyridine CCBs act?
More selective for peripheral vasculature
Have little chronotropic or inotropic effect
What are some examples of dihydropyridine CCBs?
Amlodipine
Nifedipine
What are some adverse effects of dihydropyridine CCBs?
Sympathetic nervous system activation - tachycardia
Palpitations
Flushing, sweating
Oedema
What are some types of non-dihydropyridine CCBs?
Phenylalkyamine
Benzothiazapines
What is an example of a phenylalkyamine?
Verapamil
How do phenylalkyamines work?
Depress SA node and slows AV conduction - negative inotropic effect
What is the action of phenylalkyamines?
Impedes calcium transport across myocardial and smooth muscle cell membrane
What are some adverse effects of phenylalkyamines?
Constipation
Risk of bradycardia
Negative inotrope, can worsen heart failure
What is an example of a benzothiazapine?
Diltiazem
How do benzothiazapines work?
Impedes calcium transport across myocardial and vascular smooth muscle wall
Prolongs action potential/refractory period
What are some adverse effects of benzothiazapines?
Risk of bradycardia
Can worsen heart failure
What is an example of a thiazide diuretic?
Bendroflumethiazide
How do thiazide diuretics work?
Inhibit Na+ reabsorption in the DCT
Results in diuresis therefore lowering blood and ECF
Leads to lower TPR
What are some adverse effects of thiazide diuretics?
Hypokalaemia Increased uric levels Impaired glucose tolerance Increased cholesterol and triglyceride levels Activation of RAAS
What are the NICE guidelines for treating a patient <55yrs with primary HTN?
Step 1 - ACE inhibitor or ARB
Step 2 - ACE inhibitor/ARB and CCB or thiazide diuretic
Step 3 - ACE inhibitor/ARB, CCB and diuretic
Step 4 - all of the above, βB or spironolactone
What are the NICE guidelines for treating a patient >55yrs or African/Caribbean origin with primary hypertension?
Step 1 - CCB or thiazide like diuretic
Step 2 - ACE inhibitor/ARB and CCB or thiazide diuretic
Step 3 - ACE inhibitor/ARB, CCB and diuretic
Step 4 - all of the above, βB or spironolactone
What is an example of an α-adrenoceptor blocker?
Doxazosin
How do α-adrenoceptor blockers work?
Antagonise the contraction effects of noradrenaline on vascular smooth muscle
Reduce peripheral resistance
Safe in renal disease
What are some adverse effects of α-adrenoceptor blockers?
Postural hypotension due to compromised baroreceptor reflex
Headache and fatigue
Oedema
What is an example of a β-blocker?
Bisoprolol
How do β-blockers exert their anti-hypertensive effects?
Decrease sympathetic tone by blocking noradrenaline and reducing myocardial contraction
Leads to reduced cardiac output
What are some adverse effects of β-blockers?
Bronchoconstriction - contraindicated in asthmatics and COPD pts Tachycardia Lethargy and impaired concentration Reduced exercise tolerance Bradycardia Raynaud’s
How is heart failure managed?
Diuretics are used to manage symptoms, but have little impact on survival
Furosemide is typically used
How do β-blockers exert their effects in heart failure?
Slower HR => longer diastolic filling period => increased filling => increased output
May also stabilise electrical conduction => reduced arrhythmias
May also inhibit renin, but this is a minor effect as ACE-inhibitors probs also being used
