CVS

Question 1

Digoxin: Mechanism of Action

Answer 1

It is negatively chronotropic as it slows conduction at the AV node by increasing vagal tone.
It is positively intotropic as it inhibits Na+/K+ pumps. This causes an increase in intracellular sodium, and therefore reduces Ca2+ excretion so Ca2+ accumulates in the myocytes and their contractility is increased.

Question 2

Digoxin: Indications

Answer 2

AF and atrial flutter, though a B blocker or CCB is usually more effective
In severe heart failure, as 3rd line treatment after B blocker and ACEI and spironolactone/ARB

Question 3

Digoxin: Adverse Effects

Answer 3

Bradycardia, GI upset, rash, dizziness, visual disturbance.

It is pro-arrhythmic

Question 4

Digoxin: Warnings and Interactions

Answer 4

Low therapeutic index. OD can cause weird and wonderful arythmias.
It is contraindicated in those at risk of ventricular arrhythmia or heart block
It is really excreted so dose should be reduced in renal impairment
Hypokalaemia and hypercalcaemia increase the risk of digoxin toxicity

Interacts with loop/thiazide diuretics as they can cause hypokalaemia

Question 5

Digoxin: Prescription

Answer 5

Oral or IV
Large volume of distribution so loading dose is required
Cardiac monitoring!

Question 6

Diuretics, Loop (Furosemide): Mechanism of Action

Answer 6

Inhibit Na/K/2Cl transporter in ascending limb. Also causes dilation of capacitance veins.

Question 7

Diuretics, Loop (Furosemide): Indication

Answer 7

Acute pulmonary oedema
Chronic heart failure
Other oedematous states

Question 8

Diuretics, Loop (Furosemide): Adverse effects

Answer 8

Dehydration, hypovolemia, loss of electrolytes

Hearing loss at high doses

Question 9

Diuretics, Loop (Furosemide): Warnings and Interactions

Answer 9

Contraindicated in dehydration or hypotension, and hypokalaemia
Can worsen gout as they inhibit uric acid excretion

Increase levels of renal excreted drugs
Increase ototoxicity of ahminoglycosides
Cause digoxin toxicity by hypokalaemia

Question 10

Diuretics, Loop (Furosemide): Prescription

Answer 10

Oral and IV

Periodic monitoring of electrolytes for safety

Question 11

CCBs (Amlodipine): Indications

Answer 11

Hypertension

Non-dihydropyridine drugs (verapamil) are anti-arrhythmic and can be used to treat SVT, AF and flutter

Question 12

CCBs (Amlodipine): Mechanism of Action

Answer 12

Decrease Ca2+ entry, so decrease smooth muscle contractility. They also slow conduction, especially across the AV node.

Question 13

CCBs (Amlodipine): Adverse Effects

Answer 13

Ankle swelling, flushing, headache and palpitations

Verapamil can cause bradycardia

Question 14

CCBs (Amlodipine): Warnings and Interactions

Answer 14

Verapamil SHOULD NOT be prescribed alongside a B blocker as this can cause dangerous bradycardia or even ayststole
Should be avoided in unstable angina as they can increase myocardial oxygen demand

Question 15

CCBs (Amlodipine): Prescription

Answer 15

Taken orally (except verapamil can be given IV for acute arrhythmia)
Amlodipine has a long half life so can be given once daily
Monitering is based on symptoms and BP measurements

Question 16

Lidocaine: Indications

Answer 16

Local anaesthetic

Uncommonly as anti arrhythmic for VT and VF that cannot be cardioverted

Question 17

Lidocaine: Mechanism of Action

Answer 17

Na+ channel blocker, so prevents initiation and propagation of action potentials
In the heart it reduces the duration of the action potential, slows conduction and increases the refractory period

Question 18

Lidocaine: Adverse Effects

Answer 18

Drowsiness, tremor, fits
Effects more pronounced when used systemically
OD can cause hypotension and arrhythmia

Question 19

Lidocaine: Warnings and Interactions

Answer 19

Dose reduction in patients with reduced CO

Beneficial interaction with adrenaline (local vasoconstrictor)

Question 20

Lidocaine: Prescription

Answer 20

Maximum dose is based on body weight

Foundation doctors should not prescribe it systemically

Question 21

Amiodarone: Indictions

Answer 21

A wide range of tachyarrhythmias e.g. AF, SVT, VT, VF…

Generally when other treatments have been ineffective

Question 22

Amiodarone: Mechanism of Action

Answer 22

It is a Class III drug so blocks K+ channels (It actually also blocks Ca2+, Na+ and antagonises adrenoreceptors)
This reduces spontaneous depolarisation, decreases conduction velocity and increases resistance to depolarisation

Question 23

Amiodarone: Adverse Effects

Answer 23

Hypotension

When taken chronically: pneumonitis, hepatitis, bradycardia

Question 24

Amiodarone: Warnings and Interactions

Answer 24

Actually quite a dangerous drug, so consider risks and benefits
Avoid in thyroid disease, hypotension or heart block
It interacts with lots and lots of drugs; especially digoxin and verapamil

Question 25

Amiodarone: Prescription

Answer 25

Requires senior input | Continous cardiac monitoring

Question 26

Beta Adrenoceptor Blockers: Indications

Answer 26

``` Ischaemic Heart Disease Chronic Heart Failure Atrial Fibrillation SVT HTN, when ACEIs and CCBs have not worked ```

Question 27

Beta Adrenoceptor Blockers: Mechanism of Action

Answer 27

Then antagonise B1 receptors. They are negatively chronotropic and inotropic They also increase the refractory period at the AV node They reduce renin secretion

Question 28

Beta Adrenoceptor Blockers: Adverse Effects

Answer 28

Hypotension, cold peripheries, GI upset, fatigue, headache

Question 29

Beta Adrenoceptor Blockers: Warnings and Interactions

Answer 29

Should be avoided in asthmatics (bronchospasm) In heart failure, start at a low dose and slowly increase as they can initially impair cardiac function AVOID with VERAPAMIL as this is bad (bradycardia, asystole)

Question 30

Beta Adrenoceptor Blockers: Prescription

Answer 30

Monitoring is based on symptoms and heart rate | Timing doesn't matter

Question 31

ACEI: indications

Answer 31

First line treatment of HTN Heart failure Ischaemic Heart Disease

Question 32

ACEI: Mechanism of Action

Answer 32

Inhibit ACE. Reduces AT2 levels, so reduces after load. Reduces aldosterone levels so less sodium retention

Question 33

ACEI: Adverse Effects

Answer 33

Coughing, hypotension, | Rare: idiosyncratic angiooedema

Question 34

ACEI: Warnings and Interactions

Answer 34

Can cause hyperkalaemia and worsen renal failure, so should be avoided in AKI Should be avoided in combination with other potassium elevating drugs Combination with NSAID increases the risk of renal failure

Question 35

ACEI: Prescription

Answer 35

Taken orally Can be useful to take before bed to reduce hypotension Tell patient to avoid NSAIDs Monitoring is based on symptoms, BP and checking electrolytes for safety before treatment and after 1-2 weeks

Question 36

ARB: Indications

Answer 36

HTN , esp. when ACEI is not tolerated

Question 37

ARB: Mechanism of Action

Answer 37

Block AT1 receptor | Reduces vasoconstriction and aldosterone levels

Question 38

ARB: Adverse Effects

Answer 38

Hypotension, hyperkalaemia and renal failure

Question 39

ARB: Warnings and Interactions

Answer 39

Avoid in renal disease e.g. AKI Avoid in combination with other potassium elevating drugs Combination with NSAIDs increases risk of renal failure

Question 40

ARB: Prescription

Answer 40

Taken orally, dose before bed to reduce effects of hypotension Advise to avoid NSAIDs Monitoring is based on symptoms, BP and checking electrolytes for safety before treatment and after 1-2 weeks

Question 41

Statins: Indications

Answer 41

Primary and prevention of cardiovascular disease | Primary hyperlipidaemia

Question 42

Statins: Mechanism of Action

Answer 42

Inhibit HMG-CoA Reductase so decrease cholesterol production by the liver and reduce LDL/Cholesterol levels

Question 43

Statins: Adverse Effects

Answer 43

Generally well tolerated: headache, nausea, muscle aches Rarely cause more serious muscle issues : rhabdomyolysis, myopathy Rare but serious: hepatitis

Question 44

Statins: Warning and Interactions

Answer 44

Caution in hepatic impairment Dose reduction in renal impairment CYP450 interactions!

Question 45

Statins: Prescription

Answer 45

Taken orally once daily Lipid level before starting treatment ALT/AST for safety