cardiac Flashcards
what are some examples for loop diuretics
furosemide, bumetanide - ide
indication for loop diuretics
for relief of breathlessness in acute pulmonary oedema in conjunction with oxygen and nitrates
for symptomatic treatment of fluid overload in chronic heart failure
for symptomatic treatment of fluid overload in other oedematous statues
MOA for loop diuretics
work on the ascending limb of the loop of Henle where they inhibits the Na+/K+/2Cl- co-tranpsorters
this transporter transfer water into epithelial cells and so water can follow and inhibiting this can lead to the diuretic effects
also have a dilatation of capacitance veins of vessels and reduces preload and improves contractile function of the heart muscle
contra-indication for loop diuretics
severe hypovalemia or dehydration
should be used with caution in pts at risk of hepatic encephalopathy - hypokalaemia can cause or worsen coma
avoid use in those with hypokalaemia and/or hyponatraemia
if taken chronically, loop diuretics inhibits uric acid excreation and this can worsen gout
side-effect of loop diuretics
dehydration and hypotension
should associate diuretics with almost any low electrolye state - as eliminating eletrolytes is how the loop diuretic work
the co-transporter also regulate endolymph in the inner ear and so in high dose it can lead to hearing loss and tinnitus
interaction of loop diuretics
affects drugs that are excreted in the kidneys
lithium level might inc
digoxin toxicity might inc
inc ototoxicity and nephrotoxicity of aminoglycoside
what are some examples of thiazide
thiazide, thiazide-like (bendroflumenthiazide, indapamide, chlortalidone)
MOA for thiazide
inhibits the Na+/Cl- co-tranpsorter in the distal convoluted tubule of the nephron
prevent reabsorption of Na+ and hence water
also cause vasodilation
indiction for thiazide diuretics
alternative 1st line treatment for hypertension where calcium channel blocker would otherwise be used
also add-on treatment for hypertension in pts whose blood pressure is not adequately controlled by calcium channel blocker plus an ACEi or ARB
contra-indication for thiazide diuretics
hypokalaemia and hyponatreamia
as they reduce urine excretion they can worse gout
side-effect of thiazide
hyponatreamia hypokalaemia cardiac arhythmias might inc plasma conc of glucose, LDL-cholesterol and triglycerides can also cause impotence in men
What are some examples for aldosteron antagonist
Spironolactone,epleronone
MOA for amiloride
potassium sparing diuretics are relatively weak diuretics alone but in combination with another diuretics, they can counteract potassium loss
amiloride - act in the distal convulated tubules in the kidney, inhibits reabsorption of sodium and hence water by epithelial sodium channels leading to sodium and water excreation and retention of potassium
tends to be used in a combination with furosemide (as co-amilofruse) or with hydrochlorothiazide (as co-amilozide)
Indication for aldosteron antagonist
Ascites and oedema due to liver cirrhosis - spironolactone 1st line
Chronic heart failure - usually as an addition to beta blocker and ACEi/ARB
Primary hyperalderstonism
Contraindiction for aldersteron antagonist
Severe renal impairment
Hyperkalaemia
Addison’s disease (who are aldersteron deficiency)
Avoid using in pregnant women as it can cross placenta
side effect of amiloride
GI upsets
if used with other diuretics -dizzines, hypotension, urinary symptoms
electolyte distrubance should cancel each other out but still risk of hypokalaemia, hyperkalaemia and hyponateraemia
interaction of amiloride
do not use in combination with other potassium elevating drugs incl potassium supplement and aldosteron antagonists due to risk of hyperkalaemia
renal clearnace of digoxin and lithium maybe altered
what are some examples of potassium sparing diuretics
amiloride (as co-amilfruse, am-amilzide)
what are some examples for beta-blockers
bisoprolol, atenolol, propranolol, metoprolol -olol
MOA for beta-blockers
beta1-adrenoreceptros are located mainly in the heart where beta2-adrenoreceptors are found mostly in smooth muscle of blood vessels and airways
through beta1-adenoreceptors, beta blocker reduce force of contraction and speed of conduction in the heart – relieves MI by reducing cardiac work and oxygen demand and inc myocardial perfusion
can also slow the ventricular rate of atrial fibrillation mainly by prolonging the refractory period of the AV node
SVT often involves a self-perpetuating circuit that takes in the AV node, beta-blocker stops this circuit and restore sinus rhythm
beta-blockers lower BP through reducing renin secretion from the kidney since this is mediated by beta1-adeoreceptors
indiction for beta-blockers
ischaemic heart disease - 1st line option to improve symtpoms and prognosis associated with angina and acute coronary syndrome
chronic heart failure - first line option to improve prognosis
atrial fibriliation - 1st line option to reduce the ventricular rate and in paroxysmal AF to main sinus rhythm
SVT - 1st line option in pt without circulatory comprosie to restore sinus rhythm
hypertension - maybe be used when other agents eg calcium channel blockers, ACEi, thiazide diuretics are insufficient or inappropriate
contraindiction for betablocker
asthma - bronchospam and should be avoid
when used in heart failure, dose should start low and inc slowly as it might initially damage cardiac function
contraindicated for heart block
should be avoid in pts with haemodynamic instability
significant reduction should be done when in hepatic failure
interaction of amiloride
do nor sure in combination with other potassium elevating drugs incl potassium supplement and aldosteron antagonists due to risk of hyperkalaemia
renal clearnace of digoxin and lithium maybe altered
where are beta-blockers eliminated
kidney and liver
side effect of beta blockers
fatique, cold extremities, headache and GI disturbance
can cause sleep disturbance and nightmare
can also cause impotence in men
indiction for beta-blockers
ischaemic heart disease - 1st line option to improve symtpoms and prognosis associated with angina and acute coronary syndrome
chronic heart failure - first line option to improve prognosis
atrial fibriliation - 1st line option to reduce the ventricular rate and in paroxysmal AF to main sinus rhythm
SVT - 1st line option in pt without circulatory comprosie to restore sinus rhythm
hypertension - maybe be used when other agents eg calcium channel blockers, ACEi, thiazide diuretics are insufficient or inappropriate
contraindiction for betablocker
asthma - bronchospam and should be avoid
when used in heart failure, dose should start low and inc slowly as it might initially damage cardiac function
contraindicated for heart block
should be avoid in pts with haemodynamic instability
significant reduction should be done when in hepatic failure
interaction of beta-blockers
non-dihydropyridine calcium channel blockers eg verapamil, diltiazem - can cause heart failure , bradycardia and even asystole
side effect of beta blockers
fatique, cold extremities, headache and GI disturbance
can cause sleep disturbance and nightmare
can also cause impotence in men
side effect of aldosterone antagonist
hyperkalaemia - leads to muscle weakness, arrhythmia and even cardiac arrest
spionolactone can cause gynaecomastia
can cause liver impairment and jaundice and can cause Stevens-Johnson syndrome and bullous skin eruption
interaction of aldersterone antagonist
combination with other potassium elevating drug incl ACEi and ARB inc risk of hyperkalaemia
should not be used with potassium supplements
where is aldersterone aner tagonist eliminated
liver
contraindication for aldosterone
pt with severe renal impairment, hyperkalaemia and Addison’s disease (aldosterone deficient)
pregnant women as it can cross placenta
MOA for calcium channel blockers
reduce Ca2+ entry into vascular and cardiac cells - relaxation and vasodilation in arterial smooth muscle, lowering arterial pressure
in the heart, calcium channel blocker reduce myocardial contractility
it also suppress cardiac conduction (esp across the AV node) slowing ventricular rate
reduced cardiac rate, contractility and afterload reduce myocardial oxygen demand preventing angina
CCB can be divided into 2 classes - dihydropyridines, incl amlodipine and nifedipine (relatively selective for vasculature), non-dihydropyridines (more selective for the heart)
indication for calcium channel blockers
amlodipine and nifedipine are used for the first or second line treatment for HTN to reduce risk of stroke, MI and death from cardiovascular disease
all CCB can be used to control symptoms in people with stable angina, beta-blockers are the main alternative
dilitiazem and verapamil are used to control cardiac rate in ppl with supraventricular arrhythmias incl SVT, artial flutter and AF
contra-indiction for CCB
verapamil and diltiazem should be used with caution with pts with poor left ventricular function - can precipitate or worsen HF.
should avoid in ppl with AV nodal conduction delay - may provoke heart blocker
unstable angina with amlodipine and nifedipine as vasodilation causes a reflex inc in contractility and tachycardia - inc myocardial oxygen demand
severe aortic stenosis - amlodine and nifedipine should be avoided as they can provoke collapse
interaction of CCB
non-dihydropyridine calcium channel blockers should not be perscribed with beta-blockers - can cause heart failure , bradycardia and even asystole
where are CCB eliminated
kidney
side effect of CCB
amlodipine and nifedipine - incl ankle swelling, flushing headache and palpitations (caused by the vasodilation and compensatory tachycardia)
verapamil - constipation and less common bradycardia, heart block and cardiac failure
what are some examples of ACEi
Ramipril, lisinopril, perindopril - pril
MOA for ACEi
blocks the action of ACE to prevent the conversion of angiotensin I to angiotensin II (vasoconstrictor and stimulates aldosterone secretion)
blocking angiotensin converting then reduces peripheral vascular resistance which lower BP (afterload)
it also dilute the efferent glomerular arteriole which reduces intraglomerular pressure and slow the progression of CKD
reducing aldosterone level promotes sodium and water excretion and this helps to reduce venous return (preload) which has a beneficial effect in heart failure
indication for ACEi
hypertension - 1st or 2nd treatment for hypertension to reduce the risk of stroke, MI and death from cardiovascular disease
chronic heart failure - 1st line treatment for all grade of HF
ischaemic heart disease - reduce the risk of subsequent cardivascular events
diabetic nephropathy and CKD with proteinuria - to reduce proteinurai and progression of nephropathy
side effect of ACEi
hypotension
persistent dry cough (inc level of bradykinin which is usually inactivated by ACE)
hyperkalaemia
cause or worsen renal failure - esp in pt with renal artery stenosis as they rely on efferent glomerular arteriole to maintain glomerular filtration
can cause angioedema and other anaphylactoid reactions
interaction fo ACEi
avoid using with other postasium elvating drugs eg potassium sparing diuretics and potassium supplements
inc risk of renal failure - NSAIDs
interactions of bendroflumenthiazide
NSAIDs - reduce effectiveness
combination treatment with loop diuretics - hypokalaemia
examples of calcium antagonist
amlodipline, nifedipine, diltiazem, verapamil
contrac-indication for ACEi and AT1 Blocker
AKI
renal artery stenosis
pregnancy/breastfeeding
