Besides being fun to say, Amiodarone is no joke.
In the Emergency Setting, it is used for atrial and ventricular cardiac arrhythmia’s, you know the kind you press code blue for and pee your pants a little. It also has some not so awesome side effects that you NEED to consider when giving this medication. So what do you need to know about this medication?
Glad.you.asked… because if you hadn’t, I would have told you anyway…
Amiodarone is class III anti-arrhythmic agent…
A complex drug that does complex things, working in many different ways.
How does Amiodarone work?
- It works by stimulating adrenergic receptors
- Stimulating adrenergic receptors BLOCKS alpha and beta receptors from doing their thing.
- Lengthens cardiac action potential and refractory period
- It gets bossy with sodium, calcium and potassium channels.
- Ca and K channel blocking creates negative dromotropic effects
- Na channel blocking slows depolarization
These actions cause:
- The heart rate to slow down
- This also decreases cardiac cell excitability, allowing the heart to reset back to a regular normal sinus rhythm electrical activity.
So we have talked about the anti-arrhythmic part of Amiodarone, but what does the “class” have to do with anything?
So what I am saying is you should know the difference. Here’s the break down.
- Class I: Blocks sodium channels that are rapidly firing.
- Example: Lidocaine, Procainamide, Phenytoin
- Class II: Blocks beta-adrenergic receptors.
- Example: Propranolol, Esmolol, Metoprolol
- Class III: Blocks potassium channels lengthening cardiac action potential.
- Example: Amiodarone, Ibutilide, Sotalol
- Class IV: Blocks L-type Ca Channels
- Example: Verapamil, Diltiazem
What adverse effects can happen with Amiodarone?
This medication is U-G-L-Y.
One of the most concerning side effects of amiodarone is Pulmonary Fibrosis. This is not reversible and makes breathing very hard for your patient, you know, for the rest of their life.
Another side effect is Cataracts. And if those changes aren’t enough, your skin can turn gray…WUT… This is due to liver toxicity, cause this medication is very liver toxic.
Yup, the patient can also get hypothyroidism, hyperthyroidism, neuralgia… The list goes on.
Getting cloudy vision, gray skin, new random nerve pain and having a hard time breathing is scary when you think about it, but then again so is V-Tach…
Speaking of V-Tach… the most important thing to know about this medication is that it can cause the patient who ISN’T in V-Tach, to go into V-Tach…
You read that right.
Oh yeah, and the SECOND most important thing to know about this medication is that is has a horribly long half life. So if a patient is having an adverse reaction, they will be having it for a while. FUN.
How do I give Amiodarone in an Emergency?
My favorite meme that helps me remember things in a panic emergency is from my favorite movie, The Emperors New Groove.
Knowing your IV dosages, push speeds, compatibility, etc. is important to know. Check out this pocket guide that I use to check myself if I don’t remember: IV Therapy Notes
Please note, if the patient is stable, like V-Tach with a pulse, push over 10 minutes.
In Pulseless V-Tach (AKA unstable V-Tach): The first dose is 300mg. And just like the movie 300, you shall
push slam this medication while (quietly whispering under your breath) “This is Amiooooo!”
If the initial dose doesn’t work, I then you give half of the original dose (so 150mg). Imagine the same scene but with half the amount of gusto, maybe giving it like a question… “This is amio?” and pushing half the amount too.
Get it? The first dose of amiodarone is 300mg and to remember that, you will quote the movie 300 to remind you of not only the dose but the speed at which you will push it….
Well, however you want to remember it…