Cardiovascular Drugs

Question 1

How does furosemide work?

Answer 1

inhibits Na+/K+/2Cl- transporter on loop of Henle
prevents water resorption into cells
dilates capitance veins - improves contractile function

Question 2

Indications for furosemide use?

Answer 2

Relief of oedematous states, e.g. SoB in pulmonary oedema sure to LVF failure

Question 3

side effects of furosemide?

Answer 3

postural hypotension, dehydration, electrolyte disturbance - hypokalaemia, hyperglycaemia
Oto/nephrotoxicity - when combined with other ototoxic drugs, e.g. aminoglycosides

Question 4

risks of prescribing furosemide with digoxin?

Answer 4

hypokalaemia

increased effects of digoxin and risk of dysrhythmias, toxicity

Question 5

Give an example of a thiazide diuretic

Answer 5

Bendroflumethiazide

Indapamide, Chortalidone

Question 6

How do thiazide diuretics work?

Answer 6

Inhibit Na+/Cl- transporter in distal tubule

over time peripheral resistance reduced

Question 7

side effects of thiazide diuretics?

Answer 7

hyponatraemia
hypokalaemia
postural hypotension
increased conc of glucose, cholesterol

Question 8

What type of diuretic is spironolactone, and give some combi-names

Answer 8

Potassium sparing diuretic

Amiloride, Co-amilofruse

Question 9

How does spironolactone work?

Answer 9

Aldosterone antagonist in collecting duct
decreases resorption of Na+ and water
limits K+ excretion

Question 10

Give some examples of beta-blockers

Answer 10

Atenolol, bisoprolol, propranolol, metoprolol

Question 11

How do beta-blockers work?

Answer 11

block beta1 adrenergic receptors on heart muscle
reduce force of contraction and speed of conduction
reduces renin secretion

Question 12

Indications for beta blockers?

Answer 12

Ischaemic heart disease
chronic heart failure
atrial fibrillation
SVT, hypertension, MI prophylaxis

Question 13

indications for use of spironolactone?

Answer 13

oedema, ascites (cirrhosis), nephrotic syndrome, congestive HF

Question 14

contraindication for prescribing beta-blockers

Answer 14

asthma - life threatening bronchospasm
low dose in HF as can impair cardiac function
heart block

Question 15

which beta-blockers are cardioselective, i.e. just block B1

Answer 15

atenolol, propranolol, carvedilol

Question 16

important interactions of beta-blockers

Answer 16

verapamil, diltiazem - can cause heart failure, bradycardia, asystole

Question 17

name 2 calcium agonists

Answer 17

Diltiazem (verapamil)
Amlodipine
Non-dihydropyridine calcium channel blocker

Question 18

How does diltiazem work?

Answer 18

inhibits Ca influx into vascular smooth muscle&raquo_space; relaxation

slows sino-atrial node

Question 19

What is diltiazem (verapamil) used for?

Answer 19

Angina treatment / prophylaxis
hypertension
dysrhythmias

Question 20

Contraindications of calcium channel blockers

Answer 20

severe bradycardia, heart failure, heart block

Question 21

Side effects of CCBs?

Answer 21

postural hypotension, bradycardia, ankle swelling, dizziness

Question 22

Describe the action of ramipril

Answer 22

Blocks the action of ACE
prevents vasoconstriction and aldosterone secretion
reduces peripheral resistance
dilates efferent glomerular arteriole

Question 23

Why cant you prescribe ramipril in renal artery stenosis

Answer 23

Pt relies on constriction of efferent glomerular arteriole to maintain glomerular filtration

Question 24

Potential side effects of ramipril?

Answer 24

First dose hypotension
persistent dry cough
hyperkalaemia (due to low aldosterone)
renal failure
angioedema

Question 25

what is losartan and how does it work?

Answer 25

Angiotensin receptor 1 blocker (ARB) | blocks action of angiotensin II on AT1 receptor

Question 26

Indications to prescribe losartan

Answer 26

HTN control, where ACEi not tolerated due to cough

Question 27

How does isosorbide mononitrate work

Answer 27

nitrates converted to NO reduces intracellular Ca2+ causes relaxation of vascular smooth muscle improves coronary perfusion

Question 28

Indications for isosorbide mononitrate

Answer 28

acute angina and chest pain, relief and prophylaxis

Question 29

contraindications for the use of nitrates

Answer 29

severe aortic stenosis, as heart cannot increase CO sufficiently to get blood through narrowed valve

Question 30

what type of drug is Digoxin, and how does it work?

Answer 30

Cardiac glycoside increases parasympathetic (vagal) tone, reducing contraction at AV node, ventricular rate causes accumulation of Ca2+, increasing contractile force

Question 31

Indications for digoxin

Answer 31

Atrial fibrillation, flutter | severe heart failure (3rd line)

Question 32

contra-indications of digoxin

Answer 32

heart block as may worsen conduction | electrolyte abnormalities increase risk of toxicity

Question 33

what is the effect of digoxin toxicity and what can cause it?

Answer 33

arrhythmias, due to narrow therapeutic window | loop/thiazide diuretics (hypokalaemia)

Question 34

how does Amiodarone work?

Answer 34

blocks sodium, calcium and potassium channels | antagonist of alpha/beta adrenergic receptors

Question 35

what is the overall effect of amiodarone

Answer 35

anti-dysrhythmic reduce spontaneous depolarisation slow conduction resistance to depolarisation

Question 36

Indications for amiodarone

Answer 36

tachyarrhythmias e.g. AF, SVT, VT increases time before a heart cell can contract again

Question 37

what are the side effects of amiodarone

Answer 37

lung toxicity - pneumonitis severe bradycardia hepatitis, skin photosensitivity, thyroid problems

Question 38

why does amiodarone have so many interactions

Answer 38

inhibits the action of CyP450s, reducing the clearance of many drugs

Question 39

How does aspirin work?

Answer 39

Inhibits COX enzymes, preventing production of prostaglandins (pain) and thromboxane (anti-platelet)

Question 40

key ingredient in aspirin?

Answer 40

acetylsalycylic acid | ASA

Question 41

Contra-indications for aspirin

Answer 41

``` under 16s - Reye's syndrome Aspirin hypersensitivity 3rd trimester pregnancy Peptic ulcer disease gout ```

Question 42

How does clopidogrel work?

Answer 42

binds to receptors on surface of platelets, prevents platelet aggregation

Question 43

How does streptokinase work?

Answer 43

Thrombolytic | converts plasminogen to plasmin, which lyses fibrin within thrombus

Question 44

How does heparin/fondaparinux work?

Answer 44

Inhibits thrombin and factor Xa in coagulation pathway

Question 45

How can heparin be reversed?

Answer 45

Protamine, to reverse anticoagulation

Question 46

Give examples of LMWH

Answer 46

dalteparin and enoxaparin preferentially inhibit factor Xa don't need laboratory monitoring

Question 47

Mechanism of action of warfarin

Answer 47

inhibits vitamin K epoxide reductase

Question 48

Can warfarin be used to prevent arterial thrombosis

Answer 48

No, as this is driven by platelet aggregation

Question 49

Contraindications of warfarin

Answer 49

surgery, bleed risk, liver disease as cannot metabolise Pregnancy - foetal malformations

Question 50

examples of CyP450 inhibitors

Answer 50

amiodarone, diltiazem, fluconazole, macrolides, protease inhibitors

Question 51

examples of CyP450 inducers

Answer 51

phenytoin, carbamazepine, rifampicin

Question 52

How do antibiotics and warfarin interact?

Answer 52

can increase anticoagulation by killing gut flora which synthesis vitamin K

Question 53

describe Warfarin's therapeutic window

Answer 53

Narrow therapeutic window | low therapeutic index

Question 54

How does Rivaroxaban work?

Answer 54

selective factor Xa inhibitor | affects both intrinsic and extrinsic coagulation pathways

Question 55

How are warfarin and Rivaroxaban reversed

Answer 55

Warfarin - large dose vitamin K | Rivaroxaban cannot be reversed

Question 56

How does simvastatin work?

Answer 56

inhibits HMG CoA reductase | decreases cholesterol production, increases LDL clearance from the blood

Question 57

contraindications for statins

Answer 57

hepatic and renal impairment - dose reduction | avoid in pregnancy

Question 58

why should you not suddenly withdraw diltiazem

Answer 58

may exacerbate angina

Question 59

which drugs may increase potassium levels

Answer 59

ACEi, NSAIDs, ARB, potassium salts