Ischaemic Heart Disease Flashcards
1
Q
Angiotensin Receptor Blockers
Losartan, candesartan
Common indications
A
- NB ARBs are used when ACEI are not tolerated
- HTN- 1st or 2nd line treatment to reduce risk of stroke MI and CVD
- Chronic heart failure- 1st line treatment of all grades of HF to improve symptoms and reduce cardiac remodelling
- Ischaemic heart disease- reduce risk of subsequent CV events such as MI and stroke
- Diabetic neuropathy and CKD with proteinuria- to reduce proteinuria and progression of nephropathy
2
Q
ARB
MOA
A
- ARBs and ACEI have similar effects
- ACEI= inhibit angiotensin (AG) 1 => AG2
- ARBs= block action of AG2 on AT1-receptor
- AG2 is a vasoconstrictor and stimulates aldosterone secretion
- Blocking action reduces peripheral vascular resistance (afterload), which lowers BP
- It dilates the efferent glomerular arteriole, which reduces intraglomerular pressure and reduces progression of CKD
- Reducing aldosterone level promotes Na + H20 excretion
- This can help reduce venous return (pre-load), which has a beneficial effect in HF
3
Q
ARB
Adverse effects
A
- ARBs can cause hypotension (particularly after the first dose), hyperkalemia and renal failure. The mechanism is the same as for ACEI
- Patients most at risk of renal failure are those with renal artery stenosis, who rely on the constriction of the efferent arterioles to maintain glomerular filtration
- Unlike ACEI, ARBs are less likely to cause a dry cough, as they do not inhibit ACE and therefore do not affect bradykinin metabolism
- For the same reason, they are less likely to cause angioedema
4
Q
ARB
Warnings
A
- ARBs should be avoided in patients with renal artery stenosis or AKI
- Women who are pregnant or those breastfeeding
- Although ARB therapy is potentially valuable in some forms of CKD- lower doses should be used and the effect of renal function monitored closely
5
Q
ARB
Interaction
A
- Due to the risk of hyperkalaemia, avoid prescribing ARB with other potassium-elevating drugs- including potassium supplements and potassium-sparing diuretics
- In combination with other diuretics they may be associated with profound first-dose hypotension
- The combination of NSAIDs with ARBs increase the risk of renal failure
6
Q
ARBs
Communication
A
- Explain that you are offering treatment with medicine to improve their BP and reduce strain on their heart
- If a patient has previously not tolerated ACEI due to cough state this does not cause a cough
- State possibility of dizziness (Hypotension) due to low BP, particularly after the first dose
- Make sure they understand the need for blood test monitoring, explaining that ARBs can interfere with their kidney function and upset potassium balance
- Advise them to avoid taking OTC anti-inflammatories (e.g. ibuprofen) due to risk of kidney damage
7
Q
ARBs
Monitoring
A
- Monitor efficacy clinically, for example, reduced symptoms of breathlessness in HF or improved BP control in HTN
- For safety, check electrolytes and renal function before starting treatment
- Repeat 1-2 weeks into treatment and after increasing the dose
- Biochemical changes can be tolerated provided they are within certain limits, the creatinine concentration should not rise by more than 30%, the eGFR should not fall by more than 25%, and the potassium concentration should not rise above
- If any of these limits are exceeded, you should stop the drug and seek expert advice
8
Q
ACEI
Common indications
A
- HTN- for 1st or 2nd treatment of HTN to reduce the risk of stroke, MI and death from CVD
- Chronic HF- 1st line treatment of all grades of HF, to improve symptoms and prognosis
- Ischaemic heart disease- reduce the risk of subsequent CV events such as MI and stroke
- Diabetic nephropathy and CKD with proteinuria- reduce proteinuria and progression of nephropathy
9
Q
ACEI
MOA
A
- ACEI block the action of the ACEI, to prevent the conversion of Angiotensin AG1 to AG2
- AG2 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 (preload), which has beneficial effect in HF
10
Q
ARBs
Adverse effects
A
- Common side effects include hypotension (particularly after the first dose, persistent dry cough (increased levels of bradykinin, which are usually inactivated by ACE) and hyperkalemia (low aldosterone level promotes K retention)
- They can cause or worsen renal failure. This is particularly relevant in patients with renal artery stenosis, who rely on constriction of the efferent glomerular arteriole to maintain glomerular filtration
- It detected early, these adverse effects are usually reversible on stopping the drug
- Rare but important side effects include angioedema and anaphylactoid reactions
11
Q
ACEI
Warnings
A
- ACEI should be avoided in patients with renal artery stenosis or AKI. In women who are or could become pregnant and those who are breastfeeding.
- Although ACEI is potentially valuable in some forms of CKD- lower doses should be used and the effect on renal function monitored closely
12
Q
ACEI
Interactions
A
- Due to the risk of hyperkalaemia, avoid prescribing ACEI with other potassium-elevating drugs, including potassium supplements and potassium-sparing diuretics except under specialist advice for advanced HF
- In combination with other diuretics, they may be associated with first-dose hypotension
- The combination of an NSAID and an ACEI increases the risk of renal failure
13
Q
ACEI
Communication
A
- Explain that you are offering treatment with medicine to improve BP and reduce cardiac strain (remodelling)
- Advise patients about common side effects such as a dry cough, and about the possibility of dizziness due to low BP, particularly after the first dose
- Mention that, very rarely these medicines cause effects similar to severe allergic reactions and to stop taking and seek medical advice if they develop facial swelling and stomach pain
- Make sure they understand the need for blood test monitoring, explaining ACEI can interfere with kidney function and K balance
- Avoid NSAIDs due to risk of kidney damage
14
Q
ACEI
Monitoring
A
- Monitor efficacy e.g. SOB in HF patients
- For safety check electrolyte and renal function before starting treatment, repeat these after 1-2 weeks and then after increasing the dose and after increasing the dose
- Biochemical changes can be tolerated provided there within certain limits, the creatinine concentration should not rise by more than 30%
- K should not be above 6mmol/L
15
Q
Aspirin
Common indications
A
- For the treatment of acute coronary syndrome and acute ischaemic, where rapid inhibition of platelet aggregation can prevent or limit arterial thrombosis and reduce subsequent mortality
- For long-term CV secondary prevention of thrombotic arterial events in patient with cardiovascular, cerebrovascular and peripheral arterial disease
- To reduce the risk of intracardiac thrombus of embolic stroke in AF where warfarin and NOACs are contraindicated
- To control mild-to-moderate pain and fever
16
Q
Aspirin
MOA
A
- Thrombotic events occur when platelet-rich thrombus forms in atheromatous arteries and occludes the circulation
- Aspirin irreversibly inhibits COX to reduce production of pro-aggregatory factor thromboxane from arachidonic acid, reducing platelet aggregation and the risk of arterial occlusion
- The antiplatelet effect of aspirin occurs at low doses and lasts for the lifetime of a platelet (which does not have a nucleus to allow synthesis of new COX) and thus only wears off as new platelets are made
17
Q
Aspirin
Adverse effects
A
- The most common adverse effect of aspirin is GI irritation
- More serious effects include GI ulceration and haemorrhage and hypersensitivity including bronchospasm
- In regular high-dose therapy aspirin causes tinnitus
- Aspirin is life-threatening in overdose
- Features include hyperventilation, hearing changes, metabolic acidosis and confusion, followed by convulsions, CV collapse and respiratory arrest
18
Q
Aspirin
Warnings
A
- Aspirin should not be given to children U16 due to the risk of Reye’s syndrome, a rare but life-threatening illness that principally affects the liver and brain
- It should not be taken by people with aspirin hypersensitivity i.e. who have had bronchospasm or other allergic symptoms triggered by exposure to aspirin or another NSAID
- However, is not routinely contraindicated in Asthma
- Aspirin should be avoided in the third trimester of pregnancy when prostaglandin inhibition may lead to premature closure of the ductus arteriosus
- Aspirin should be used with caution in people with peptic ulceration (e.g. prescribe GI protection) or Gout as it may trigger an acute attack