Pharmacology Part 2

Question 1

Class 1 Antiarrhythmics are what and act as what?

Answer 1

Na Channel blockers that act as local anesthetics

Question 2

What is the mechanism of class I antiarrhythmics?

Answer 2

• Slow or block conduction
• Decrease slope of phase 0 depolarization
• Increase threshold for firing in abnormal pacemaker cells

Question 3

Class I antiarrhythmics are ______ dependant and selectively depress what?

Answer 3

state

tissue that is frequently depolarized (tachycardia)

Question 4

______ causes increased toxicity for all class I drugs

Answer 4

Hyperkalemia

Question 5

Name the Class Ia antiarrhythmic drugs

Answer 5

Double Quarter Pounder:
Disopyramide
Quinidine
Procainamide

Question 6

What is the mechanism of class IA antiarrhythmics?

Answer 6

1. Incease AP duration
2. Increase ERP
3. Increase QT interval

Question 7

What is class Ia used for?

Answer 7

• Atrial arrhytmia
• ventricular arrhythmia
• reenterant/ectopic SVT and VT

Question 8

What is Quinidines toxicity?

Answer 8

Cinchonism-headache, tinnitus

Question 9

What is Procainamides toxicity?

Answer 9

Reversible SLE-like syndrome

Question 10

What is disopyramides toxicity?

Answer 10

Heart failure

Question 11

What toxicity is caused by all type Ia antiarrhythmics?

Answer 11

thrombocytopenia

torsades de pointes due to long QT interval

Question 12

What are the class IB drugs?

Answer 12

Lettuce Tomato Mayo:
Lidocaine
Tocainide
Mexiletine

Question 13

What does class IB do?

Answer 13

Decrease AP duration

Question 14

Class IB preferentially affects hat?

Answer 14

ischemic or depolarized purkinje and ventricular tissue

Question 15

What is class IB used in?

Answer 15

• Acute Ventricular Arrhythmia (esp post-MI)

- Digitalis induced arrhythmia

Question 16

What is the toxicity with class IB?

Answer 16

• Local anesthetic
• CNS stimulation/depression
• CV depression

Question 17

Class IB is best used when?

Answer 17

post-MI

Question 18

What other drug can fall in the class IB category?

Answer 18

Phenytoin

Question 19

What are the class IC drugs?

Answer 19

Fries Please:
Flecainide
Propafenone

Question 20

What is the effect on AP duration of class Ic?

Answer 20

NONE

Question 21

What is Class IC useful in?

Answer 21

• Ventricular tachycardia that progress to VF
• intractible SVT
• Last resort in refractory tachyarrhythmias

Question 22

Class IC is for patients without what?

Answer 22

structural abnormalities

Question 23

What is the toxicity of class IC?

Answer 23

• Proarrhythmic (esp Post-MI…contraindicated)

- Prolongs refractory period in AV node

Question 24

What type of antiarrhythmics are class II?

Answer 24

Beta blockers

Question 25

Name the class II antiarrhythmics?

Answer 25

``` Metoprolol Propranolol Esmolol Atenolol Timolol ```

Question 26

What is the mechanism of class II?

Answer 26

Decrease SA/AV node activity by decreasing cAMP and Ca currents

Question 27

Class II suppresses abnormal pacemakers by doing what?

Answer 27

decreasing slope of phase 4

Question 28

Which node is particularly sensitive to class II and what is prolongued?

Answer 28

AV node, PR interval

Question 29

Which class II drug is very short acting?

Answer 29

Esmolol

Question 30

What are the toxcitiy of class II?

Answer 30

- Impotence - Exacerbation of asthma - CV effects - CNS effects - Masks signs of hypoglycemia

Question 31

What are the CV side effects from class II?

Answer 31

bradycardia AV block CHF

Question 32

What are the CNS side effects from class II?

Answer 32

sedation | sleep alterations

Question 33

Metoprolol can cause what side effect and how do you treat overdose of this?

Answer 33

dyslipidemia, glucagon

Question 34

Propranolol can exacerbate what?

Answer 34

vasospasm in Prinzmetal's angina

Question 35

What do the class III antiarrhythmics do?

Answer 35

K channel blockers?

Question 36

What are the class III antiarrhythmics?

Answer 36

``` AIDS? Amiodarone Ibutilide Dofetilide Sotalol ```

Question 37

What is the mechanism of class III?

Answer 37

Increase AP duration and ERP | Increases QT interval

Question 38

When are class III used?

Answer 38

When other antiarrhythmics fail

Question 39

What is the toxicity with Sotalol?

Answer 39

Torsades de pointes | Excess Beta Block

Question 40

What is Ibutilides toxicity?

Answer 40

Torsades de pointes

Question 41

What are amiodarones toxicity?

Answer 41

- Pulmonary Fibrosis - hepatotoxicity - hypo/hyperthyroidism (bcz 40% iodine by weight) - Corneal deposits - Skin deposits (blue/gray)-->photodermatitis - Neurologic effects - Constipation - CV effects (bradycardia, Heart block, CHF)

Question 42

Amiodarone has class I, II, III, and IV effects why?

Answer 42

Alters the lipid membrane

Question 43

With amiodarone remember to check what?

Answer 43

PFT, LFT, TFT

Question 44

What do the Class IV drugs do?

Answer 44

Ca channel blockers

Question 45

What are the class IV drugs?

Answer 45

Verapamil | Diltiazem

Question 46

What is the mechanism for class IV?

Answer 46

- Decrease conduction velocity - increase ERP - increase PR interval

Question 47

What are class IV used to prevent?

Answer 47

Nodal arrhythmias (eg. SVT)

Question 48

What is the toxicity of class IV?

Answer 48

- Constipation - Flushing - Edema - CV effects (CHF, AV block, sinus node depression)

Question 49

What is the mechanism of adenosine?

Answer 49

Increased K out of cells causes hyperpolarizing of the cell and decreased intracellular Ca

Question 50

What is adenosine the drug of choice in?

Answer 50

Diagnosing/abolishing SVT

Question 51

Is adenosine long or short acting?

Answer 51

Short (15 sec)

Question 52

What is the toxicity of Adenosine?

Answer 52

- Flushing - Hypotension - Chest pain

Question 53

Effects of adenosine are blocked by what?

Answer 53

Theophylline and caffeine

Question 54

What is Mg2+ effective in?

Answer 54

- Torsades de pointes | - Digoxin Toxicity