antiarrhythmic agents1

Question 1

what is the MOA of drugs on EKG for treating arrhythmias

Answer 1

interrupting QT interval

Question 2

what part of ekg depicts atrial depolarization?

Answer 2

p wave

Question 3

what part of ekg depicts ventricular depolarization

Answer 3

qrs wave

Question 4

what part of ekg depicts refractory period

Answer 4

qt interval

Question 5

what is the term for regular rhythm of heart; between 60-100 bpm.

Answer 5

normal sinus rhythm (NSR)

Question 6

what is torsade de pointes

Answer 6

a polymorphous ventricular tachycardia with prolonged QT interval

Question 7

what is a palpitation

Answer 7

an awareness of the heartbeat; with or without an irregular rhythm

Question 8

what are the 3 primary MOAs of antiarrhythmics

Answer 8

1. changing conduction velocity
2. changing refractory peiod
3. changing automoticity

Question 9

what are the effects of VW type 1a on:

1. conduction velocity
2. refractory period
3. automaticity

Answer 9

1. decrease velocity
2. increase refractory period
3. decrease automoticity

Question 10

what are the effects of VW type 1b on:

1. conduction velocity
2. refractory period
3. automaticity

Answer 10

1. decrease velocity
2. decrease refractory period
3. decrease automoticity

Question 11

what are the effects of VW type 1b on:

1. conduction velocity
2. refractory period
3. automaticity

Answer 11

1. strongly decrease velocity
2. no change on refractory period
3. decrease automoticity

Question 12

anything that works on K channel is likely to cause what?

Answer 12

torsades

Question 13

what subtype of of type 1 antiarrhythmics prolong ventricular refractoriness and QT interval by blocking K channels

Answer 13

type 1a

Question 14

what VW class antiarrhythmic increases mortality in structural heart disease

Answer 14

class 1a and 1c

Question 15

what is a classic example of a VW type 1b drug?

what does it work best for

Answer 15

lidocaine

MI’s with ventricular arrhythmias

Question 16

why shouldnt lidocaine be used for a long period

Answer 16

metabolites have competitive action at site of action

Question 17

what are type 2 antiarrhythmics

Answer 17

Beta blockers

Question 18

what are the B-1 antagonists antiarrhythmic MOA

Answer 18

lowers HR and FOC, decreasing oxygen demand.

Question 19

what is the primary MOA of amiodarone

Answer 19

blockade of potassium channels

Question 20

what is the major type 1a drugs

Answer 20

1. quinidine
2. procainamide
3. disopyramide

Question 21

what drug consistently proves superior to treating atrial fibrillations

Answer 21

amiodorone

Question 22

what is the lowest effective dose of amiodorone for atrial fibrillation

Answer 22

200 mg/ day

Question 23

what is the lowest effective dose of amiodorone for ventricular tachycardia

Answer 23

400 mg/ day

Question 24

why are daily doses of amiodorone divided

Answer 24

adverse GI effects; not due to half life!

Question 25

what are the contraindications for amiodorone?

what doasage adjustment bust be made for renal dysfunction

Answer 25

kidney

no changes in dosing for renal dysfunction

Question 26

what is the most common antiarrhythmic agent?

why?

Answer 26

amiodorone

lowest proarrhythmic potential

Question 27

what is important with kinetics of amiodorone?

Answer 27

highly distributed in tissue; blood levels are useless

Question 28

what is the half life of amiodorone

Answer 28

53 days

Question 29

what determines how adverse effects will be seen in patients on amiodorone

Answer 29

amount taken and time on the drug

Question 30

what is the #1 concerning adverse effect of amiodorone

Answer 30

pulmonary fibrosis; rapidly progressive and potentially fatal

Question 31

what is the effect on the thyroid of amiodorone

Answer 31

usually hypothyroidism; sometimes hyperthyroidism