Drug therapies for hypertension and angina Flashcards
Hypertension increases your risk of what disease?
Cardiovascular disease
What is a greater risk factor for cardiovascular disease?
a) increased systolic BP
b) increased diastolic BP
Systolic
What is the difference between systolic and diastolic BP?
Systolic = pressure your heart exerts whilst beating Diastolic = amount of pressure in your arteries between beats
What are the symptoms of hypertension?
usually no symptoms unless very severe = silent killer
What causes hypertension? (5)
Complex interaction of genes and environment Renal or endocrine disease Vascular disease (renal artery stenosis) Drugs (amphetamines)
Describe the renin-angiotensin system?
Reduced glomerular filtration leads to reduced sodium in distal tubule.
This cases increased renin release.
Renin converts angiotensinogen to angiotensin I
Angiotensin I converted to Angiotensin II by ACE.
Angiotensin II cuases negative feedback loop to reduce renin release
What is the function of angiotensin II?
Peripheral vasoconstriction and aldosterone secretion.
Causes negative feedback loop to reduce renin release
What is the function of aldosterone?
Increase peripheral resistance, activate sympathetic nervous system. Increase HR and BP. Stimulates kidneys to retain Na which raises BP
What is the aim of hypertension management?
Prevent myocardial infarction and stroke (reduce risk of heart failure)
How is hypertension managed?
Lifestyle advice and drug treatment
What is ABPM?
Ambulatory blood pressure monitoring
What is HBPM?
Home blood pressure monitoring
How can hypertension be classified?
Stage 1
Stage 2
Severe
If a patient is diagnosed with stage 1 hypertension what is the course of action?
Monitor lifestyle modification and arrange 24 hour monitoring
What is the course of action for stage 2 hypertension?
Lifestyle modification fairly urgent 24hours monitoring
What is the course of action for severe hypertension?
Treat immediately - emergency
What lifestyle changes can be used to manage hypertension?
Lose weight Exercise Smoking Diet - salt Manage other vascular risk factors e.g. cholesterol, diabetes
Function of ACE inhibitors?
Inhibit ACE - inhibits formation of angiotensin II. Inhibits aldosterone secretion = no increase in BP
What is the bets choice of drug for a patient under 55 with hypertenison?
ACE inhibitors
What is the choice of drug fro patient over age 55 with hypertension?
Calcium-channel blocker
Describe the mechanism of action of thiazide like diuretics?
Increase excretion of Na and water
More Na reaches the distal tubule
BP lowering related to decreased peripheral reisstance
Mechanism of beta blockers?
Decrease HR, decrease myocardial contractility, inhibit renin-angiotensin system (reduce peripheral resistance)
Adverse effects of beta blockers?
Heart failure fatigue Blunting recognition of hypoglycaemia in diabetes Withdrawal tooth demineralisation
Calcium channel blockers mechanism of action?
Block Ca entry into smooth muscle cells, inhibit Ca current in sinus and AV node
Decrease peripheral resistance, decrease HR, decrease coronary vascular resistance
Adverse effects of calcium channel blockers?
Flushing, headaches, oedema, bradycardia, heart failure
Adverse effects of ACE inhibits
Renal failure
Cough
Burning mouth syndrome
Describe angiotensin receptor blockers mechanism of action?
Inhibit action of angiotensin II at receptor
Effect of angiotensin receptor blockers?
Decrease sympathetic nervous system, vasodilation
Mehcanism of action of alpha blockers?
Alpha - adrenoreceptor antagonist.
Vasodilation = fall in BP
Increase HR
What is the aim of management of angina?
Reduce symptoms and reduce risk of MI stroke
What risk factors need to be managed for treatment of angina?
Vascular risk factors e.g. smoking, cholesterol, diabetes
What is the effect of anti-platelet therapy for angina treatment?
Reduces risk of NI and stroke
Mechanism of action of nitrates for angina teatment?
Relax arterial and venous smooth muscle. Venodilation = reduced BP
Redistribution of blood flow to ischaemic myocardium
Disadvantages of nitrate therapy to treat angina?
Tolerance - decreased effect at given concentration. after repeated doses
Effect of catecholamines like adrenaline and noradrenaline on oxygen demand?
Increase myocardial oxygen demand during exercise by effecting HR and contractility
Effect of B blockers on oxygen demand?
Decrease myocardial oxygen demand by decreasing the effects of noradrenaline and adrenaline
Effect of B blockers on angina?
Reduces effects of adrenaline = reduce oxygen demand during exercise = angina tolerance improved
Effect of If channel blockers (in the sinus node)?
lowers HR without any other action on cardiac function
