Antiarrhythmic agent

Class

Potent antiarrhythmic agent and the first-line antiarrhythmic agent given during cardiac arrest.

Has been clinically demonstrated to improve the rate of ROSC and hospital admission in adults with refractory ventricular fibrillation and pulseless ventricular tachycardia.

Description

Prolongs the action potential duration in all cardiac tissues.

Affects sodium, potassium, and calcium channels and has alpha- and beta- adrenergic blocking properties.

Mechanism of Action

How Supplied

Amiodarone Hydrochloride Injection, 50 mg/mL is supplied in:

3 mL (150 mg)

Life-threatening cardiac arrhythmias such as ventricular tachycardia and ventricular fibrillation. Also:

Stable, regular, and wide complex tachycardia.

To control rapid ventricular rate due to accessory pathway.

Indications

cardiogenic shock

Severe sinus node dysfunction resulting in marked sinus bradycardia.

Second- or third-degree AV block

Symptomatic bradycardia.

Known hypersensitivity.

Contraindications

Use with caution in patients with latent or manifest heart failure because failure may be worsened by its administration.

Precautions

Monitor the patient’s ECG for:

Bradycardia

Increased ventricular beats

Prolonged PR interval, QRS complex, and QT interval

Watch for signs of pulmonary toxicity such as dyspnea and cough.

Hypotension

Side Effects

Hypotension is the most common adverse effect seen with Amiodarone and may be related to the rate of infusion. Hypotension should be treated by slowing the infusion or with standard therapy: vasopressor drugs, positive inotropic agents, and volume expansion.

The most important treatment-emergent adverse effects are hypotension (16%), bradycardia (4.9%), liver function test abnormalities (3.4%), cardiac arrest (2.9%), VT (2.4%), CHF (2.1%), cardiogenic shock (1.3%), and AV block (0.5%).

Amiodarone

May react with:

Warfarin

Digoxin

Procainamide

Quinidine

Phenytoin

Interactions

Why is Amiodarone only diluted in D5W?

This is the only fluid in which

amiodarone is stable. Amiodarone when mixed in other fluids can precipitate out into solid form.

https://acls-algorithms.com

Three or more ventricular complexes in succession at a rate of 100 beats per minute or more

Overrides the heart’s normal pacemaker

Ventricular Tachycardia

Bledsoe/Porter/Cherry/Snyder, Intermediate Emergency Care: 1985, Third Edition

©2008 by Pearson Education, Inc., Upper Saddle River, NJ

Ventricular Tachycardia

Bledsoe/Porter/Cherry/Snyder, Intermediate Emergency Care: 1985, Third Edition

©2008 by Pearson Education, Inc., Upper Saddle River, NJ

Wide complex > 0.12 secs

Myocardial ischemia

Increased sympathetic tone

Hypoxia

Idiopathic causes

Acid-base disturbances

Electrolyte imbalances

Etiology

Bledsoe/Porter/Cherry/Snyder, Intermediate Emergency Care: 1985, Third Edition

©2008 by Pearson Education, Inc., Upper Saddle River, NJ

Usually results in poor stroke volume

Patients may have a normal blood pressure, may be hypotensive, or may be in cardiac arrest

Ventricular tachycardia is always significant

Whether ventricular tachycardia is perfusing or non-perfusing dictates the treatment

Ventricular tachycardia may eventually deteriorate into ventricular fibrillation

Clinical Significance

Bledsoe/Porter/Cherry/Snyder, Intermediate Emergency Care: 1985, Third Edition

©2008 by Pearson Education, Inc., Upper Saddle River, NJ

Stable patient with a pulse

Administer oxygen and place an IV line

Administer amiodarone 150 milligrams over 10 minutes

Repeat as needed to a maximum dose of 2.2 grams over 24 hours

If patient is or becomes unstable, as evidenced by chest pain, altered level of consciousness, or falling blood pressure, initiate cardioversion immediately after placing an IV line and administering oxygen. If time allows, sedate the patient first.

Pulseless patient should be treated as ventricular fibrillation

Treatment

Bledsoe/Porter/Cherry/Snyder, Intermediate Emergency Care: 1985, Third Edition

©2008 by Pearson Education, Inc., Upper Saddle River, NJ

CCFEMS Protocol Adult Tachycardia

For regular rhythm, monomorphic complex

this means V-tach or SVT with Aberrancy

*consider adenosine 6mg rapid push, may repeat 12mg IV/IO x 2

IF rhythm does not covert NEXT • Amiodarone 150mg in 100ml of D5W over 10 minutes

(15mg/min), may repeat x 1 if no response

Dosage-Wide Complex Tachycardia (with a pulse)

100 mls

Dosage-Wide Complex Tachycardia (with a pulse) continued

Next if still no response •Amiodarone 450mg /250 ml’s of D5W (1mg/min or 33ml/hr)

Chaotic ventricular rhythm usually resulting from the presence of many reentry circuits within the ventricles

There is no ventricular depolarization or contraction

No organized rhythm

P waves, PR interval, and QRS complex absent

Ventricular Fibrillation

Bledsoe/Porter/Cherry/Snyder, Intermediate Emergency Care: 1985, Third Edition

©2008 by Pearson Education, Inc., Upper Saddle River, NJ

Ventricular Fibrillation

Bledsoe/Porter/Cherry/Snyder, Intermediate Emergency Care: 1985, Third Edition

©2008 by Pearson Education, Inc., Upper Saddle River, NJ

A wide variety of causes have been associated with ventricular fibrillation

Most cases result from advanced coronary artery disease

Etiology

Bledsoe/Porter/Cherry/Snyder, Intermediate Emergency Care: 1985, Third Edition

©2008 by Pearson Education, Inc., Upper Saddle River, NJ

Ventricular fibrillation is a lethal dysrhythmia

The absence of cardiac output or an organized electrical pattern results in cardiac arrest

Clinical Significance

Bledsoe/Porter/Cherry/Snyder, Intermediate Emergency Care: 1985, Third Edition

©2008 by Pearson Education, Inc., Upper Saddle River, NJ

CCFEMS Protocol V-Fib, Pulseless V-tach

Initial dose is 300 mg IV push.

Repeat at 150 mg IV if no response.

Dosage Ventricular fibrillation or pulseless ventricular tachycardia

DosageVentricular fibrillation or pulseless ventricular tachycardia

IF RHYTHM CONVERTS:

administer 1mg/min or 450mg/250 ml D5W (33ml/hr) IV or IO