amiodarone Flashcards
preparation
Ampoule containing 150 mg in 3 ml.
what is it
antidysrhythmic with a broad spectrum of activity.
MOA
predominatly block the potassium channels, but it can also block sodium and calcium channels and the beta and alpha adrenergic receptors stopping overactive signals thus:
prolongs the action potential duration prolongs the refractory period
reduces automaticity
resulting in decreased HR and stabilisation of the nodes
indications
Cardiac arrest with VF or VT at any time after the first dose of adrenaline
ICP
Adults with sustained VT in the absence of cardiac arrest.
Adults with moderate cardiovascular compromise as a result of fast atrial fibrillation or fast atrial flutter.
contraindications
Known severe allergy
Known severe allergy to iodine.
VT secondary to cyclic antidepressant poisoning. In this setting amiodarone administration can be associated with severe worsening of shock, without resolution of the rhythm.
cautions
NONE IN CARDIAC ARREST
1. Poor perfusion or signs of low cardiac output. Amiodarone reduces inotropy and may cause a significant fall in cardiac output, particularly when administered rapidly.
2.Hypotension. Amiodarone causes vasodilation and may worsen hypotension, particularly when administered rapidly.
3.Atrial fibrillation associated with sepsis. Amiodarone may cause a significant fall in cardiac output.
4.Known sick sinus syndrome without an internal pacemaker in place. Amiodarone slows the heart rate and severe bradycardia may occur following reversion of a tachydysrhythmia.
5.Previous 2nd or 3rd degree heart block without an internal pacemaker in place. Amiodarone slows the heart rate and severe bradycardia may occur following reversion of a tachydysrhythmia.
6.Pregnancy.
giving in pregnancy??
do not give unless strong clinical indication to
dosage for cardiac arrest
Cardiac arrest:
300 mg for an adult.
If VF or VT persists, a second dose of 150 mg may be administered.
adverse effects
Hypotension.
Lightheadedness.
Bradydysrhythmia.
onset
5-10 mins
duration
1-4 hours after a single dose.
why can amiodarone have a longer duration when multiple doses are given
Amiodarone is taken up into tissues and slowly released. This may result in a prolonged half-life, particularly when more than one dose has been administered.
goal of amiodarone in moderate comp AF
goal of treatment is to control the ventricular rate and not to revert the rhythm to sinus rhythm, although treatment with amiodarone may result in reversion of the rhythm to sinus rhythm. If a patient has been in atrial fibrillation for longer than a few days, there is a small risk that this may be associated with emboli leaving the left atrium. This is why amiodarone is reserved for patients with cardiovascular compromise that is clinically significant.
what to do if patient reverts before full dose is given
If amiodarone is commenced, the full dose should be administered even if the rhythm reverts to sinus rhythm, unless severe hypotension or bradycardia occurs.
