Pharmacology

Question 1

Class IA, IB and IC drugs act upon which ion pathway during AP formation?

Answer 1

Sodium ion channel.

Drugs of this classification are referred to as Sodium Channel Blockers.

Question 2

Do class I drugs prolong or shorten the ventricular action potential?

Answer 2

Class I drugs prolong the ventricular action potential.

Question 3

True or False:

A prolonged ventricular action potential will result in prolonged AA / VV intervals.

Answer 3

False - It will result in shorter AA / VV intervals.

Resultantly there is less chance for re-entrant tachycardia provocation.

Question 4

Class II drugs are referred to as _______ Blockers.

Answer 4

Beta Blockers.

Question 5

Class III drugs act upon which ion pathway during action potential formation?

Answer 5

Potassium ion pathway.

Referred to as Potassium channel blockers.

Question 6

Class IV drugs act upon which ion pathway during action potential formation?

Answer 6

Calcium ion pathway.

Referred to as Calcium channel blockers.

Question 7

List the names of two Class V drugs and which ion pathway do they act upon during AP formation?

Answer 7

Adenosine and Digoxin

Mechanisms of these two drugs are not well described.

Question 8

The following statement best describes which classification of drug?

‘Blocks beta-adrenergic binding sites in cardiac and vascular cell membranes’.

Answer 8

Class II Beta Blockers.

This mechanism moderates the effects of sympathetic activity.

Question 9

List 5 cardiac outcomes with respect to Class II beta blockade.

Answer 9

1. Decreased Inotropy (contractility)
2. Dromotropy (conduction velocity)
3. Reduced BP
4. Moderated SA node automaticity
5. Reduced ectopy

Question 10

List two common examples of Class II Beta Blockers.

Answer 10

1. Propranolol
2. Metoprolol

Question 11

The following statement best describes which classification of drug?

‘Binds to and blocks potassium channels responsible for phase 3 repolarisation​’.

Answer 11

Class III - Potassium Channel Blockers.

Question 12

The following statement best describes which single classification of drug?

‘Increases Action Potential duration and ERP’.

Answer 12

Class III - Potassium Channel Blockers.

Class IA & IC also increase APD & ERP by affecting potassium channels. Not by sodium blockade. IB decreases ERP

Question 13

List two common examples of Class III - Potassium Channel Blockers.

Answer 13

1. Amiodarone - Long half life (25-60days)
2. Sotalol - Also has class II activity

Question 14

List 3 cardiac effects of class IV drugs.

Answer 14

1. Negative Inotropy (Decreased contractility)
2. Negative chronotropy (Decreased HR)
3. Negative dromotropy (Decreased conduction velocity)

Question 15

List the 3 different types of calcium channel blockers available.

Answer 15

1. Dihydropyridines
2. Non-Dihydropyridines - Phenylalkylamine class
3. Non-Dihydropyridines - Benzothiazepine class

Question 16

The following two drugs are examples of which type of Class IV drug.

1. Amlodipine
2. Felodipine

Answer 16

Both are examples of Dihydropyridines

Question 17

The following drug is an example of which type of Class IV drug?

1. Verapamil

Answer 17

Example of Non - Dihydropyridines - Phenylalkylamine class.

Question 18

The following drug is an example of which type of Class IV drug

1. Diltiazem

Answer 18

Example of Non-Dihydropyridines - Benzothiazepine class.

Question 19

True or False:

Class II and IV drugs are suitable as a treatment strategy for Sinus Tachycardia.

Answer 19

True

Treat underlying cause first if applicable.

Question 20

Which drug classifications could be administered as a treatment arm for AF?

Answer 20

Class: IA, IC, II, III, IV.

Ventricular rate control is important here.

Question 21

What classes would you give for PSVT.

Answer 21

IA, IC, II, III, IV.

Most likely to give Adenosine (Class V), which will block the AV node.

Question 22

What drug would you give for AVB?

Answer 22

Atropine.

Question 23

What classes would you give for PVCs?

Answer 23

II or IV.

Most likely benign however - normally no treatment is required.

Question 24

What classes could you give for Digitalis toxicity.

Answer 24

IB and V (Magnesium Sulphate)

Question 25

List some common metabolic states that increase capture threshold.

Answer 25

1. Acidosis (80%) 2. Alkalosis (80%) 3. Hypercarbia 4. Hyperkalemia 5. Hyperglycaemia 6. Hypoxemia 7. MI 8. Ischemia 9. Myxoedema 10. Sleep 11. Eating

Question 26

List 4 classes of drugs that increase pacing threshold and give examples.

Answer 26

1. IA = Quinidine, Procainamide, Disopyramide 2. IC = Flecainide, Propafenone 3. III = Amiodarone 4. IV = Verapamil

Question 27

List two classes of drug which potentially increase pacing threshold.

Answer 27

1. IA - Procainamide, Quinidine 2. IB = Lidocaine

Question 28

List 4 drugs / sympathetic agents, which can decrease pacing threshold.

Answer 28

1. Atropine 2. Epinephrine 3. Isoproterenol 4. Corticosteroids

Question 29

List 3 drugs which have no known effect on threshold.

Answer 29

1. Beta Blockers 2. Digitalis 3. ACE inhibitors

Question 30

According to AHA/ACC/HRS. Which 5 drugs increase DFT?

Answer 30

1. IA = Quinidine 2: IA = Procainamide 3: IC = Flecainide 4: IC = Propafenone 5. III = Amiodarone

Question 31

According to AHA/ACC/HRS. Which drug may decrease DFT?

Answer 31

1. III = Sotalol

Question 32

List 5 cardiac drugs which are excreted via renal system.

Answer 32

1. Sotalol 2. Digoxin 3. Disopyramide 4. Bretylium 5. Tocainide

Question 33

List 5 cardiac drugs which are eliminated by the Hepatic system.

Answer 33

1. Lidocaine 2. Flecainide 3. Amiodarone 4. Verapamil 5. Propafenone

Question 34

List 3 drugs which increase digoxin potency.

Answer 34

1. Flecainide 2. Amiodarone 3. Verapamil

Question 35

List 4 Drugs which add to beta blockers potency.

Answer 35

1. Flecainide - additive to negative inotropic effect 2. Amiodarone - additive to beta blocking effect 3. Verapamil - additive to bradycardia 4. Lidocaine - Increases Beta Blocker potency

Question 36

What drug reverses the effects of: Midazolam / Diazepam / Temazepam?

Answer 36

Flumazenil.

Question 37

What drug reverses the effects of: Fentanyl / Morphine / Diamorphine?

Answer 37

Naloxone.

Question 38

Which drug class does this to the Action Potential?

Answer 38

1A = Slow conduction, Prolonged repolarisation.

Question 39

Which drug class does this to the Action Potential?

Answer 39

Class 1b = Shorter repolarisation, no effect on conduction.

Question 40

Which drug class does this to the Action Potential?

Answer 40

1c = Slow conduction, no effect on repolarisation.

Question 41

Which drug class does this to the Action Potential?

Answer 41

Class III - Prolonged repolarisation, no effect on conduction.

Question 42

Which class of drugs are pro-arrhythmic to torsades and may slow VT? (two examples)

Answer 42

Class Ia. 1. Procainamide 2. Quinidine

Question 43

Which drug class may cause central nervous system side effects? (Two examples)

Answer 43

Class Ib. 1. Lignocaine 2. Mexiletine

Question 44

Give two examples of drugs that are proarrhythmic for SCD in LV dysfunction?

Answer 44

1. Flecainide 2. Propafenone

Question 45

Which class III drug 1. Increases DFTs 2. Decreases DFTs

Answer 45

Amiodarone Increases Sotalol Decreases

Question 46

Which drug class may cause or exacerbate CHB and HF? (Two examples)

Answer 46

Class IV - Potentiates Digoxin. 1. Verapamil 2. Diltiazem

Question 47

Which class of drugs are predominantly prescribed for SVTs?

Answer 47

Class IV.

Question 48

Which class of drugs can't be used post MI? (CAST study)

Answer 48

Class I. ## Footnote *Also negatively inotropic so cannot be prescribed in patients with LV dysfunction.*

Question 49

List 3 major drawbacks of Sotalol.

Answer 49

1. Relatively high Torsades rate 2. Non cardioselective 3. Reverse use dependence

Question 50

Describe reverse use dependence.

Answer 50

Lesser effect at higher heart rates. ## Footnote *E.g. Good at preventing AF (as baseline HR is low), poor at converting AF once its started (as HR is now high).*

Question 51

Which of the following drugs is most likely to reduce DFT while minimally influencing VT CL? 1. Lidocaine 2. Flecainide 3. Sotalol 4. Amiodarone 5. Digoxin

Answer 51

3 - Sotalol.

Question 52

Which of the following is most likely to increase stim threshold post PPM implant? 1. Digoxin 2. Sotalol 3. Flecainide 4. Mexiletine

Answer 52

3 - Flecainide