what accounts for amiodarone's low toxicity? would it be a useful agent when titrated in proper proportion with adenosine (even though it's primarily used for av nodal arrhythmias)?
amiodarone vs. adenosine
- Thread starter trgf
- Start date
- Joined
- Apr 28, 2006
- Messages
- 6,133
- Reaction score
- 2,369
Amiodarone has real and severe toxicity when it is toxic. Adenosine lasts for like 6 seconds
You can't really titrate much along with adenosine because it metabolized almost immediately
You can't really titrate much along with adenosine because it metabolized almost immediately
D
da8s0859q
My thoughts also. Amiodarone likes to trash thyroid, liver, and lung function when it can, so I wouldn't say it's got a low toxicity. And iirc, adenosine is only effective for about 15 seconds or so, and is used mostly to stop SVT in its tracks.
Also, amiodarone is a potassium channel blocker, and adenosine promotes potassium efflux to hyperpolarize the cell. So functionally, you're taking one drug which causes a transient heart block (adenosine) and then throwing another one which slows repolarization time when the heart actually CAN conduct (amiodarone) on top of it. Not sure I'd want to do that.
Sorry, I meant adenosine - it's supposed to have low toxicity, while amiodarone is seen as being very efficacious. My initial conjecture was that you could get the best of both worlds if you used them in combination together; but perhaps also the worst as you have pointed out. With this in mind, I guess dronedarone would not be a good substitute agent to use with adenosine either, huh?
D
da8s0859q
That's my guess, but I'm not sure. I can see the point -- just like you'd use two drugs with a similar result by different mechanisms in other conditions -- but it just seems like an iffy idea to basically cause a heart block and then throw other antiarrhythmics in the mix. And I was under the impression that adenosine is used for very acute (or diagnostic) purposes, so it wouldn't really be something where titration with a more long-term drug would come to mind. Could be wrong.
- Joined
- Aug 6, 2010
- Messages
- 1,920
- Reaction score
- 15
For Step 1 I think the main thing is that 1. they work by 2 different mechanisms (amiodarone is a K blocker, adenosine increases K efflux) 2. adenosine is clutch for SVT but only a temporary fix like carotid massage 3. amiodarone is known for having heavy toxicities, so if someone comes in with nasty liver function tests, hyperthyroidism, and dyspnea after taking an antiarrythmic.. yeah
