Amiodarone

Question 1

Class

Answer 1

Class 3 antidysrhythmic

Question 2

Actions

Answer 2

Antidysrhythmic

Question 3

Mechanism of action

Answer 3

Class 3 drugs block K+
channels in the cell
membrane to delay
repolarisation and increase
action potential duration.
Thus, increases the
refractory period.
Amiodarone also blocks
Na+ channels and B
adrenoreceptors so has
class 1 and class 2 actions

Question 4

Clinical use

Answer 4

Atrial fibrillation and
flutter
Ventricular ectopic
beats
Tachyarrhythmia

Question 5

Adverse effects

Answer 5

Torsades de pointes
Pulmonary fibrosis
Liver damage
Photosensitive skin
rashes
Thyroid malfunction

Question 6

what is amiodarone

Answer 6

: An antianginal and antirhythmic agent (A potassium channel blocker………Amiodarone is a Vaughan-Williams Class III antiarrhythmic agent.

Question 7

what type of antiarrhythmic agent is amiodarone

Answer 7

a Vaughan-Williams Class III antiarrhythmic agent.

Question 8

what are the two major actions if the antiarrhythmic effect of amiodarone

Answer 8

1) Prolonging the myocardial cell-action potential (phase 3) duration and refractory period and
2) Acts as a noncompetitive a- and b-adrenergic inhibitor

Question 9

what are the other actions of amiodarone

Answer 9

1) b-blocker activity and calcium channel blocker-like actions on the SA and AV nodes
2) increases the refractory period via sodium- and potassium-channel effects
3) slows intra-cardiac conduction of the cardiac action potential, via sodium-channel effects.

Question 10

what has replaced Amiodarone

Answer 10

Still used but much less common as defibrillators are now inserted