Pharmacology

Question 1

Why aren’t thrombolytics used more regularly?

Answer 1

Because they are associated with increased bleeding risk; the benefits do not always outweigh the harms.

Question 2

Thrombolytics mechanism

Answer 2

• Catalyses activation of plasminogen into plasmin
• Plasmin breaks down fibrin in clots, thus dissolving them

Question 3

What are the two main thrombolytic drugs?

Answer 3

• Tenecteplase
• Alteplase

Question 4

List some conditions which beta blockers can be used to treat

Answer 4

• Heart failure
• Ischaemic heart disease
• Tachycardia
• Essential tremor

Question 5

Which beta receptors do selective/non-selective beta blockers

Answer 5

Selective: Only block beta 1
Non-selective: Block beta 1 and beta 2

Question 6

List two beta 1 selective beta blockers

Answer 6

• Atenolol, metoprolol (general)
• Nebivolol and bisoprolol (chronic systolic heart failure)

Question 7

List four beta 1 selective beta blockers

Answer 7

• Atenolol, metoprolol (general)
• Nebivolol and bisoprolol (chronic systolic heart failure)

Question 8

List three non-selective beta blockers

Answer 8

• Propanolol (chronic liver disease)
• Carvedilol (chronic heart failure)
• Labetalol (used in hypertension in pregnancy)

Question 9

Absolute contraindications for beta blockers (think about all effects of beta receptors)

Answer 9

• Hypotension
• Uncontrolled heart failure
• Severe or poorly controlled reversible airways disease

Question 10

Relative contraindications for beta blockers

Answer 10

• Diabetes (won’t be able to detect hypoglycaemia)
• Peripheral vascular disease (walking distance reduced)

Question 11

Things to communicate when starting beta blockers

Answer 11

• Dizziness/tiredness
• Do not stop treatment suddenly

Question 12

For what conditions are calcium channel blockers used?

Answer 12

• Hypertension
• Ischaemic heart disease
• Tachycardia

Question 13

Effect of calcium channel blockers on vascular smooth muscle

Answer 13

Relaxation

Question 14

Effect of calcium channel blockers on myocardium

Answer 14

Reduced contractility

Question 15

Effect of calcium channel blockers on cardiac conduction tissue

Answer 15

Reduced heart rate

Question 16

Effect of calcium channel blockers on gut

Answer 16

Relaxation of lower oesophagus (reflux) and intestine (constipation)

Question 17

What are verapamil calcium channel blockers selective for?

Answer 17

Myocardium compared to peripheral vascular tissue

Question 18

What are dihydropyridine calcium channel blockers selective for?

Answer 18

Peripheral vascular tissue

Question 19

Which patients should not be prescribed DHP calcium blockers?

Answer 19

• Low HR
• Low BP
• Cardiac conduction defect
• Systolic heart failure

Question 20

Dihydropyridines (CCB) adverse effects

Answer 20

• Vasodilation: flushing, headache
• Swelling of ankles

Question 21

How do nitrates work? How do they make it easier for the heart to circulate blood around the body?

Answer 21

• Source of NO
• Relaxes smooth muscle structures such as veins and arterioles
• Reduced venous return, reducing preload and work
• Also, arteriolar dilation, lowering blood pressure and decreasing afterload

Question 22

Ace Inhibitor suffix

Answer 22

-pril

Question 23

Side effects of ACE inhibitors?

Answer 23

• Renal failure
• Bradykinin cough
• Rarely, angioedema

Question 24

Why aren’t ARBs used all the time instead of ACE inhibitors? After all, they bypass the risk of bradykinin cough…

Answer 24

They aren’t as proven in some situations, and so ACEIs are usually used in the first instance.

Question 25

ARB suffix

Answer 25

-sartan

Question 26

What are the two classes of heparin?

Answer 26

- Unfractionated - Low molecular weight

Question 27

Why is LMW heparin considered better than unfractionated heparin?

Answer 27

- No antiplatelet effect (no thrombocytopaenia) - More reliable - Longer half life

Question 28

Antiplatelets vs anticoagulants

Answer 28

Antiplatelets: Stop platelets from clumping together Anticoagulants: Stop clotting factors that produce clots

Question 29

Heparin suffix

Answer 29

-parin

Question 30

Recall three types of heparin

Answer 30

- Enoxaparin - Dalteparin - Nadroparin

Question 31

Under what conditions would you not give a patient heparins?

Answer 31

- Active bleeding - Thrombocytopaenia (in the case of unfractionated heparins) - Renal failure (drugs are renally cleared)

Question 32

Describe heparin induced thrombocytopaenia syndrome

Answer 32

IgG antibodies against heparin-platelet complex. Causes platelet aggregation and thrombin generation. Hence, you get thromboses, as well as bleeding due to thrombocytopaenia

Question 33

What are the main adverse effects of statins?

Answer 33

- Muscle aches (myalgia) - Mysotisis (inflammation) - Myopathy (weakness) - Rhabdomyolysis (muscle death)

Question 34

What does ARNI stand for?

Answer 34

Angiotensin receptor antagonist + neprolysin inhibitor

Question 35

What type of enzyme is neprolysin? What does it do?

Answer 35

- In a class of enzymes called neutral endopeptidases - Breaks down substances such as BNP, angiotensin II, and bradykinin

Question 36

What is the effect of increased Brain Natriuretic Peptide caused by ARNIs during HF?

Answer 36

- Increased natriuresis - Decreased sympathetic tone - Decreased RAAS activation

Question 37

What is the effect of increased bradkyinin caused by ARNIs during HF?

Answer 37

Angioedema

Question 38

Why is it that neprolysin inhibitors are combined with angiotensin receptor antagonists in the case of ARNI?

Answer 38

- Neprolysin breaks down angiotensins I and II and BNP - Inhibiting neprolysin increases BNP, which is good, but also increases angiotensin II, which is bad for decreasing blood pressure - Therefore, by combining neprolysin inhibitors with ARBs, we get the best of both worlds

Question 39

Suitability issues unique to ARNIs...

Answer 39

- Contraindicated for patients with angioedema - Can't be used with ace inhibitor; increased risk of angioedema

Question 40

Provide a potential mechanism for how SGLT2 inhibitors can help in heart failure

Answer 40

- SGLT2 inhibited in the kidneys - Sodium and glucose are not reabsorbed into the bloodstream; remain in filtrate - Elevated sodium detected by macula dena - Renin release inhibited - RAAS inhibited - Blood pressure decrease

Question 41

Ivabradine basic mechanism

Answer 41

- Briefly inhibits flow of ions during cardiac pacemaker current - Increases length of diastole - Decreases heart rate