Pharm 24: Heart rhythm

Question 1

Antiarrhythmic classes

Answer 1

I: Na+ block
II: β adrenergic block
III: K+ block
IV: Ca+ channel blockers

Question 2

Na+ channel blockers MOA

Answer 2

decrease automaticity in SA nodal cells by shifting the threshold to more positive potentials and decreasing the slope of phase 4 depolarization

Question 3

Na+ blockers and defib

Answer 3

Higher voltages are needed

Question 4

NA+ blockers action on ventricular myocites

Answer 4

Decrease Phase 0 velocity, decrease automaticity

Question 5

Class 1A effects

Answer 5

Moderate Na+ Block (phase 0)
Prolonged repolarization

Question 6

Class 1B effects

Answer 6

Mild Na+ Block (phase 0)
Shortned repolarization

Question 7

Class 1C effects

Answer 7

Marked Na+ Block (phase 0)
No change in repolarization

Question 8

Quinidine class /MOA

Answer 8

1A

Also anticholinergic by blocking K+ after M2 stimulation.

Can increase AV conduction speed

Question 9

Qunidine metabolism

Answer 9

P450 (bc of this bad to give w/ digoxin)

Question 10

Procainamide Class/MOA and uses

Answer 10

1A

Used for rentry tachycardia

No anticholinergic effects

Question 11

Chronic procainimide therapy leads to

Answer 11

Lupus like syndrome

Question 12

Procainimide kinetics

Answer 12

Acetylated to N-Acetyl-procainimide (NAPA)

This is a class III for some reason

Question 13

Disopyramide MOA/class and use

Answer 13

1A Na+

Used for VTACH

Question 14

Lidocaine MOA use and class

Answer 14

1B

Bind to open and closed channels

Use for Vtach

Question 15

What class exhibits use dependent block

Answer 15

1B

Question 16

Lidocaine side effects

Answer 16

NOT torsades

CNS effects mostly

Question 17

Mexilitine MOA and use

Answer 17

1B

Basically Oral Lidocaine

used as adjunct (usually w/ amio)

Question 18

Phentoyn use and MOA

Answer 18

Mostly antiepileptic but also some 1B

Sometimes used for congenital long QT in kids

Question 19

Class 1C names

Answer 19

Flecainide (main)
Ecainide
Moricizine
Propafenone

Question 20

Flecinide class/MOA and use

Answer 20

1C

Afib with normal heart

Question 21

β Blocker generations (effects

Answer 21

1: Nonselective β antagonist
2: Selective for β1 at low dose
3: β1 and also vasodilation

Question 22

β Blocker generations (names)

Answer 22

1) Propanalol
2) Atenolol, Metoprolol, Acebutolol, Bisprolol
3) Labetalol and carvedilol

Question 23

Pindolol MOA and uses

Answer 23

β1 and β2 partial agonist

use in Hypertensive bradycardia

Question 24

Nevibolol MOA

Answer 24

β1 blocker and also NO production for vasodilation

Question 25

Labetalol/ Carvedilol MOA

Answer 25

β1 and also α-adrenegic antagonist for vasodilation

Question 26

Class II effects on action potential

Answer 26

Decrease phase 4 depolarization

Question 27

Class III effects on action potential

Answer 27

Prolonged repolarization

Question 28

Reverse use dependency (what is it and what drugs)

Answer 28

Action potential prolongation most pronounced at slow rates Ibultide, Dofetilide and Sotalol (*NOT AMIO*)

Question 29

Ibultilide class and MOA and use

Answer 29

Class III Prolongs repol Used to terminate Atrial rhythms

Question 30

Deofetilide MOA, use and class

Answer 30

Class III Oral agent Used for atrial shit

Question 31

Sotalol class, MOA and use

Answer 31

Mixed II/III Non selective β block and also K+ block

Question 32

Amiodarone class and MOA

Answer 32

Mostly III but it does what it wants Mechanism is lipid membrane alterations Lengthens refractory period Use dependent class I

Question 33

Amio Adverse effects

Answer 33

Pneumonitis w/ fibrosis Thyroid problems (hyper or hypo ) Negative inotrope when chornic Neuro shit Corneal deposits Liver shit

Question 34

Ca2+ blockers work preferentially at

Answer 34

SA and AV node

Question 35

Verapamil use

Answer 35

HTN and printzmetal angina

Question 36

Verapamil + _____ = kill

Answer 36

Beta blockers Killing happens via heart failure

Question 37

Adenosine MOA

Answer 37

P1 receptor -> G-protein K+ chanell opens —> inhibition of SA and AV conduction Also inhibits Ca2+ channel potentiation by cAMP

Question 38

Adenosinne MOA

Answer 38

Boronchoconstriction in asthma

Question 39

Ranolazine MOA and use

Answer 39

Stable angina

Question 40

Ivabradine MOA and use

Answer 40

Ivabradine inhibits the *If* current responsible for phase 4 depolarization in SA nodal cells, slowing the heart, decreasing oxygen demant

Question 41

Reverse use dependency seen in _______

Answer 41

Class III antiarrhythmics