Heart failure Flashcards
1
Q
Loop Diuretics
Common indications
A
- For relief of breathlessness in acute pulmonary oedema in conjunction with oxygen and nitrates
- For symptomatic treatment of fluid overload in HF
- Symptomatic treatment of fluid overload in other oedematous states- H+R failure, where they may be given in combination with other diuretics
2
Q
Loop diuretics
MOA
A
- As their name suggests, loop diuretics act principally on the ascending limb of the loop of Henle, where inhibit Na+/K+/2Cl- Co-transporter
- This protein is responsible for transporting sodium and potassium and chloride ions from the tubular lumen into the epithelial cell
- Water then follows by osmosis. Inhibiting this process has a potent diuretic effect
- Also, loop diuretics have a direct effect on blood vessels, causing dilation of capacitance veins
- In acute HF, this reduces preload and improves contractile function of the overstretched heart muscles
- Indeed, this is probably the main benefit of loop diuretics in acute HF, as illustrated by the fact that the clinical response is usually evident before a diuresis is established
3
Q
Loop diuretics
Adverse effects
A
- Water losses due to diuresis can lead to dehydration and hypotension
- Inhibiting the Na/K/2Cl co-transporter increases urinary sodium, chloride and pottasium loss
- Indirectly also causes increased excretion Mg, Ca and H ions
- You can therefore associate loop diuretics with almost any low electrolyte state
- A similar Na/K/2Cl co-transporter is responsible for regulating endolymph composition in the inner ear
- At high doses, loop diuretics can affect this too, leading to hearing loss and tinnitus
4
Q
Loop diuretics
Warnings
A
- Loop diuretics are contraindicated in patients with hypovolaemia or dehydration
- They should be used with caution in patients at risk of hepatic encephalopathy
- Severe hypokalaemia and hyponatraemia
- Taken chronically, loop diuretics inhibit uric acid excretion and this can worsen gout
5
Q
Loop diuretics
Interactions
A
- Loop diuretics have the potential to affect drugs that are excreted by the kidneys
- For example, Lithium levels are increased due to reduced excretion
- Digoxin toxicity may also increase
- Increase ototoxicity and nephrotoxicity of aminoglycosides
6
Q
Loop diuretics
Monitoring
A
- For safety, periodic monitoring of serum sodium, pottasium and renal function is also advisable, particularly in the first few weeks of therapy
7
Q
ACE inhibitors
Common indications
A
- Hypertension- for the first or second-line treatment of hypertension
- Chronic HF
- Ischaemic heart disease
- Diabetic nephopathy and CKD with proteinuria
8
Q
ACE inhibitors
MOA
A
- ACE inhibitors block the action of the ACE to prevent conversion of angiotensin I => II
- Angiotensin II is a vasoconstrictor and stimulates aldosterone secretion
- Blocking its action reduces peripheral vascular resistance (afterload), which lowers BP
- It particularly dilates the efferent glomerular arteriole, which reduces intraglomerular pressure and slows the progression of CKD
- Reducing the aldosterone level promotes sodium and water excretion
- This can help to reduce venous return (pre-load), which has a beneficial effect in HF
9
Q
ACE inhibitors
Adverse effects
A
- Common side effects include hypotension (particular after the first dose), persistent dry cough (due to increased levels of bradykinin, which usually inactivated by ACE) and hyperkalaemia (because a lower aldosterone level promotes potassium retention)
- They can cause or worsen renal failure
- This is particularly relevant in patients with renal artery stenosis, who rely on the constriction of the efferent glomerular arteriole to maintain glomerular filtration
- If detected early, these adverse effects are usually reversible on stopping the drug
- Rare but important side effects of ACEI include angioedema and anaphylactoid reactions
10
Q
ACE inhibitors
Warnings
A
- ACEI should be avoided in patients with renal artery stenosis or acute kidney injury
- Pregnant and breastfeeding
- CKD, lower doses should be used and the effect on renal function monitored closely
11
Q
ACE inhibitors
Interactions
A
- Due to the risk of hyperkalaemia, avoid prescribing ACEI with other potassium-elevating drugs, including supplements and K-sparring diuretics
- Incombination with other diuretics (profound first dose hypotension)
- NSAID and ACEI increases the risk of renal failure
12
Q
ACE inhibitors
Communication
A
- Take the first dose before bed to reduce symptomatic hypotension
- Common side effects: Dry cough, dizzieness, allergic reactions
- Need blood test monitoring, explaining that ACEI can interfere with renal function and upset K balance
- Advise to avoid taking OTC NSAID
13
Q
ACE inhibitors
Monitoring
A
- Monitor efficacy for reduced symptoms of breathlessness in HF
- Check electrolyte and renal function before starting treatment
- Repeat 1-2 weeks into treatment and increasing dose
- Creatinine concentration should not rise by more than 30%
- eGFR should not fall by more than 25%
- K levels should not be above 6mmol/L
14
Q
Beta-Blockers
Common indications
A
- Ischaemic heart disease- first line option to improve symptoms and prognosis associated with angina and acute coronary syndrome
- Chronic HF- as a first line option to improve prognosis
- Atrial fibrillation- As a first-line option to reduce the ventricular rate and in paroxysamal AF, to maintain sinus rhythm
- Supraventricular tachycardia (SVT)- first-line option in patients without circulatory compromise
- Hypertension
15
Q
Beta-Blockers
MOA
A
- Beta1-adrenoreceptors are located mainly in the heart, whereas B2-adrenoreceptors are found mostly in the smooth muscle of blood vessels and the airways
- Beta-Blockers reduce the force of contraction and speed of conduction in the heart
- This relieves myocardial ischaemia by reducing cardiac work and oxygen demand, and increasing myocardial perfusion
- They improve prognosis in heart failure by protecting the heart from the effect of chronic sympathetic stimulation
- They slow the ventricular rate in AF mainly by prolonging the refractory period of the atrioventricular node
- In HTN, BB lower BP through a variety of means, one of which is by reducing renin secretion from the kidney, since this is mediated by B1-receptors
16
Q
Beta-Blockers
Adverse effects
A
- Beta-Blockers commonly cause fatigue, cold extremities, headache and GI disturbances
- They can cause sleep disturbances and nightmares as well as impotence in men
17
Q
Beta-Blockers
Warnings
A
- Asthma- BB can cause life-threatening bronchospasm and should be avoided
- The effect is mediated by blockade of B2-adrenoreceptors in the airways
- BB is usually safe in COPD, although it is prudent to choose a B1 selective receptor
- In HF, BB should be started at a low dose and slowly increased, as they initially impair cardiac function
- They should be avoided in patients with haemodynamic instability and are contraindicated in heart block
- BB generally require dosage reduction in significant hepatic failure
18
Q
Beta-Blockers
Interactions + monitoring
A
- BB must not be used with non-dihydropyridine calcium channel blockers
- This combination can cause HF, bradycardia and asystole
- The best guide to dosage adjustment is the patient’s symptoms and HR should be around 60BPM
19
Q
Statins
Common indications
A
- Primary prevention of cardiovascular disease: to prevent cardiovascular events in people over 40 years of age with a 10-year cardiovascular risk >20%.
- Secondary prevention of cardiovascular disease: the first-line alongside lifestyle changes, to prevent further cardiovascular events in those who already have evidence of cardiovascular disease.
- Primary hyperlipidaemia: first-line, in conditions such as primary hypercholesterolaemia, mixed dyslipidaemia and familial hypercholesterolaemia.
20
Q
Statins
MOA
A
- Statins reduce serum cholesterol levels. They inhibit 3-hydroxy-3- methyl-glutaryl coenzyme A (HMG CoA) reductase, an enzyme involved in making cholesterol
- They decrease cholesterol production by the liver and increase the clearance of LDL-cholesterol from the blood, reducing LDL-cholesterol levels
- They also indirectly reduce triglycerides and slightly increase HDL-cholesterol levels. Through these effects, they slow the atherosclerotic process and may even reverse it
21
Q
Statins
Adverse effects
A
- Statins generally safe
- headache and GIT disturbances
- Myopathy and rhabdomyolysis
- Raise in liver enzymes
22
Q
Statins
Warnings
A
- Hepatic impairment- use with cautions
- Renal impairment- use with caution- renal excretion
- Pregnant/Breastfeeding- ChE essential for normal fetal development
23
Q
Statins
Interactions
A
- CYP P450 inhibitors (Amiodarone, diltiazem, macrolides) leads to accumulation of statin in body increasing risk of adverse effects
- Amlodipine- has a similar interaction though the mechanism is less clear. If taking the 2 together stop statin during acute antibiotic course (clarithromycin)
24
Q
Statins
Communication
A
- Should be taken in the evening, as there is some evidence that they have a greater effect when food intake is at its lowest
- Must seek medical attention if they experience muscle symptoms (pain or weakness)
- Ask for blood tests in 3 and 12 months
- Avoid grapefruit juice
25
Q
Statins
Monitoring
A
- Primary prevention of CVD- Blood test before treatment but does not need regular check-ups
- Secondary prevention-
- For safety check Lover enzymes at 3 and 12 months
- A rise in ALT up to three times the upper limit of normal may be acceptable, but above this should lead to discontinuation. The statin can be restarted at a lower dose when liver enzymes have returned to normal. You do not need to check creatine kinase routinely, but you should ask patients to report muscle symptoms
26
Q
Sacubitril
Indications + MOA
A
- Symptomatic chronic HF with reduced ejection fraction (in combo with Valsartan)
- Inhibiting neprilysin- increase cGMP, which results in vasodilation, natriuresis and diuresis, increased GFR and renal blood flow, inhibit renin and aldosterone release, Reduce sympathetic activity and antihypertrophic effect
27
Q
A
