Amiodarone Flashcards
(11 cards)
MoA
Amiodarone is an antidysrhythmic and has broad spectrum activity
Class III Activity
Predominantly class III activity. It prolongs action potential duration, reduces automaticity, and prolongs the refractory period of atrial nodal and ventricular tissues.
Predominant activity
Class III (K+ channel blocker). It prolongs action potential duration, reduces automaticity and prolongs the refractory period of atrial, nodal, and ventricular tissue.
Electrophysiology
The electrophysiological effects result in a reduction in abnormal electrical activity (e.g. ectopy), a reduction in electrical conduction, a reduction in HR and a stabilisation of the SA and AV nodes.
Other MoA
Amioderone can also cause a small increase in coronary blood flow (not usually significant), and a reduction in myocardial o2 consumption by reducing inotropy (force of contraction).
Indications
- Cardiac arrest with VF or Vt at any time after first dose of adrenaline.
- Adults with sustained VT in the absence of cardiac arrest.
- Adults with moderate cardiovascular compromise as a result of fast Af or fast AF.
Contraindications
- Allergy
- Known severe allergy to iodine
- VT secondary to cyclic antidepressant poisoning. Amioderone can severely worsen shock without resolution of VT.
Cautions
- None in CA
- Poor perfusion or signs of low CO. Amioderones reduction in inotropy can lower CO.
- Hypotension.
- Af associated with sepsis. fall in CO
- Known sick sinus syndrome with out an internal pacemaker. risk of severe brady.
- Previous 2nd or 3rd degree heart block.
- pregnancy
Dosage: Cardiac Arrest
300mg for an adult.
150mg for second dose if Vf or VT persists.
Dosage: Tachydysrhythmia
300mg IV over 30 minutes
2nd dose of 150mg of 30 minutes if tachy persists.
300mg in 100ml of glucose 5%. 1dps. flush afterwards.
Pharmacokinetics
It is metabolised in the liver
there are no significant effects from liver impairment on acute administration
