Got it, Nancy
Got it, Nancy
Why Amiodarone??
Topic created Mar 27, 2006 by An_1268201
I understand that Dig is no longer the darling of afib & also know why this is but why is Amiodarone used so widely? When I was in my ER training , the studies showed it looked promising in the field--since lidocaine was so useless--but that long term, it did not show any benefits for M&M. Now I am in FP & see this used commonly in pts with Afib, despite the fact that they are on coumadin & the rate is controlled with a BB or CCB. Why add another potentially lethal drug that has myriad SE's in addition to the Coumadin if the rate is controlled & they are anti-coagulated?? From a PCP perspepetive, this is very problematic & any help to understand this is much appreciated.
GEORITTER - 11:16pm Mar 27, 2006 (#1 of 17)
Add to 'My Discussions' | Post to this topic
I do agree with you that amio is over used. The side effects are horrendous and the benefits are indeed limited.In my opinion amio is not indicated it there is satisfactory rate control. If rate control is not satisfactory, then amio may be used with the usual caveats. Should a serious side effect occur with amio, than it should be discontinued and then consideration given to another anti rhythmic drug ( tambocor, Propafenone, or soltalol). Failing this, then AV node ablation with a pacemaker shouold be considered, or the new variations on the Cox procedure..The rate of conversion of AF of long standing to NSR is quite small, but may be worth a try (by cardioversion with one of the above meds).
An_1212761 - 11:45pm Mar 27, 2006 (#2 of 17)
Add to 'My Discussions' | Post to this topic
Amio is the most effective agent in maintaining sinus rhythm for patients with symptomatic afib. So it is frequently used in patients who breakthrough other antiarrhythmics. The AFFIRM trial did not show a mortality advantage to maintaining sinus rhythm (though it didn't show a disadvantage either) therefore rhythm control should not be the primary objective for every patient with AF but it is a worthwhile goal for those with symptoms and there are quite a few of those patients out there.
Secondly while its has horrible potential side effects, it is the safest antiarrhythmic for patients with LV dysfunction. Having a neutral effect on mortality in this group is a giant step up from all the other agents which have shown increased mortality (i.e. the CAST trial). These are also the patients that may benefit most from the slight increase in cardiac output sinus rhythm provides. Recall AFFIRM did not look at heart failure patients, so it is possible that there could be an advantage to rhythm in this group. There is a Canadian AF trial similar to AFFIRM studying these patients. And amio did suggest a benefit in the CHF-STAT and GESICA trials. (Maybe from its beta-blocker effects.)
Lastly, for the reasons listed above (least likely to cause proarrhythmia and at least a neutral mortality effect) as well as its superior efficacy you may be seeing it used to prevent recurrent shocks in the growing number of patients with ICDs.
An_1268201 - 11:39am Mar 28, 2006 (#3 of 17)
Add to 'My Discussions' | Post to this topic
THank you very much for the comments!
GEORITTER - 10:40pm Mar 29, 2006 (#4 of 17)
Add to 'My Discussions' | Post to this topic
There is no queation that amio does control arrhymias ,BUT the side effect profile affects nearly 50% of of patients on so called "low dose". (200mgm daily). If as a side effect pulmonary complications or hepatic complications ,or bleeding with coumadin on board, occurs the fatality rate is significant. For those who tolerate it , it is a good drug, but one always needs a plan B. Actually , the Cast study looked at patients who had had a prior MI with residual scar. These are very prone to dis-rhymthic events, especially certain anti rhythmic drugs..Propafeneone was not tested in the Cast study, and reports are it is "less " pro rhythmic. Should one decide to use an anti rhythmic drug, and pro-rhythnia is a possibility , hospital oserrvation is appropriate. By far, the safest course in a patient with AF, is a short trial of restoring NSR and if it fails then ask the patient to live with AF and stay on coumadin. If the AF is truly troublesome , then more aggressive treatment is indicated..A trial of amio is not a bad option but close close close observation is mandatory.
An_1264274 - 05:43pm Apr 27, 2006 (#5 of 17)
Add to 'My Discussions' | Post to this topic
The use of amio in the immediate post-op course following open heart surgery has been a major benefit in getting those patients back into normal sinus rythm. Ofcourse, it's use is limited to just 2 weeks in most post-op patients( excluding those treated with a Maze operation for a fib) so the complication rate is very low. However, I had a friend (a pathologist) who ultimately died from brochiolitis obliterans secondary to long term amiodarone use. I believe that this agent should be used very cautiously for long term atrial arrythmia suppression.
MAShapiroMD - 06:09pm Apr 27, 2006 (#6 of 17)
Add to 'My Discussions' | Post to this topic
Amiodarone has two very different side effect profiles. Long term oral use should be avoided unless there is no other viable option, such as in my adult congenitals with poorly tolerated non-ablatable right atrial tachycardias. The young "forever amio" patient will get ugly toxicities at some point. Whenever I have a patient on oral amiodarone, my thoughts are how I'm going to get them off of it; the stuff takes at least eight weeks to start to clear, so I have time to think about it, set up an ablation (I'm not an electrophysiologist), titrate other drugs, etc... I must say that I've given up on rhythm control in many of my usual hypertensive chronic A-fibbers. Until ablation is really ready for prime time, it's usually not worth the risks of the drugs that work.
The other side of amiodarone is in its short term use. There's very little pulmonary toxicity to only a few weeks or months of the stuff. I frequently give full IV loads to my fibrillating post surgical patients, while they're healing and I'm optimizing everything else. I give a nice load of amio, say 3g total, and try to maintain sinus. If I can't, then I back off and let the amio clear over the next few months, pushing the beta blockers when I can. That use is quite safe.
It does behoove our profession to look at the shameful history of antiarrythmic drugs: we killed people for four decades with poisons like quinidine and procaineamide just because they had PVCs. We killed people with digoxin and its like for two centuries, til we learned better dosing with the DIG trial and its subgroups. So I am very conservative with the drugs that haven't been demonstrated to save lives, and very aggressive with those that have. Just my $0.02.
--MAShapiro MD FACC The Cook County Hospital, Chicago
carmkb - 06:12pm Apr 27, 2006 (#7 of 17)
Add to 'My Discussions' | Post to this topic
Amiodarone is only useful to treat older patients who are highly symptomatic despite rate control. There are monitoring guidelines which should be followed. I use it much more often in patients who have frequent VT precipitating ICD shocks, to decrease the frequency of the shocks.
mjmpar - 06:15pm Apr 27, 2006 (#8 of 17)
Add to 'My Discussions' | Post to this topic
I limit my pt's to 5 x's a week at 200mg. My results are good with AF-- Thank G-- no problems in the last 10 years. I wonder however if anyone would comment on the effects of the deposits in the crystaline lens of the eyes???
An_1211221 - 06:36pm Apr 27, 2006 (#9 of 17)
Add to 'My Discussions' | Post to this topic
I am not a cardiologist, or even a primary care doc. However, I did have PAF for 11 years. I went through the gamut of several drugs including amiodarone to control and prevent events. Fortunately, the only perceptible side effect was an elevation of my TSH, which returned to normal within 6 months of cessation. In any case I found that eventually I would have breakthrough, and require another medication. The most recent one was flecainide, which was probably the most successful of the lot. However, about 10 months ago I had a PV ablation with some ancillary ablations as well. I have been free of any AF since then. I certainly would consider this as a viable alternative to any medications. The risks in capable hands is very small, certainly when compared to some fo the problems with the medications. Certainly, it is more effective and has less morbidity than AV ablation (which is now considered obsolete) and the Maze procedure (if done as a stand-alone procedure.
carmkb - 07:03pm Apr 27, 2006 (#10 of 17)
Add to 'My Discussions' | Post to this topic
Re: corneal deposits: no problem. Ignore them and try to get your ophthalmologist or optometrist to do so too. They are universal in amio treated patients, do not affect vision and go away after stopping the drug. Hypothyroidism due to amiodarone is generally not an indication to stop the drug - just add replacement therapy. AV node ablation/pacemaker is certainly not obsolete in the older patient (I did one today on a 90 year old woman who already had a pacemaker, due to heart rates in the 180s and multiple drug intolerances. Anybody who would have subjected her to an attempt at curative ablation would be crazy). Curative ablation for AF is an option for selected patients. Despite what some centers are claiming (90% "cure" rates with one procedure) the real numbers are about 50 - 60% cure rate for a single procedure for PAF and 80 - 90% after a second procedure. For persistent or chronic AF the numbers are about 20 points lower.
lcroninmd - 07:40pm Apr 27, 2006 (#11 of 17)
Add to 'My Discussions' | Post to this topic
Once you have given up on maintaining NSR, there is no role for amiodarone in AF. That said, I have a small handful of patients who tolerate AF so very poorly (one ends up on the vent nearly every time he fibrillates--ischemic CM and very poor reserve) that it seems worthwhile to keep them on a small dose to increase their odds of maintaining NSR. I try to get away with as little as possible, usually 100mg/day with labs every 6 months, CXR and PFT yearly.
msacket - 08:15pm Apr 27, 2006 (#12 of 17)
Add to 'My Discussions' | Post to this topic
Amiodarone is a good drug for the right patient. However first line agents for most pts are 1C drugs like rhythmol and flecainide. These are vastly underused. People are afraid of the CAST data but these are very safe drugs for pts with no CAD and nl LV function. For pts with stuctural heart dz however the options arelimited. However we probably should be using more Tikosyn and even sotalol before resorting to amio in younger pts (even those in early 60's) who will require drugs for a long time. IN these pts curative ablation is a great choice but as someone already noted, the success rates aren't 90% but more like 60% on the first attempt. Amio still has a place and now I am telling my amio pts that i expect to get them off of it in two years when alternative drugs like dronaderone or azimilide become available. Amio is also a great drug for rate control in older pts, hypotensive pts who dont tolerate other drugs.
nbishopric - 08:46pm Apr 27, 2006 (#13 of 17)
Add to 'My Discussions' | Post to this topic
I find a lot of patients come in after post-surgical atrial fibrillation in the distant past, or on large doses of amiodarone that have never been adjusted after loading. Follow-up with these patients is vital, since our surgeons often don't have the time to step down the amiodarone in their postop visits.
szevon - 08:50pm Apr 27, 2006 (#14 of 17)
Add to 'My Discussions' | Post to this topic
a 78 year old patient with well controlled hypertension, and paroxsysmal atrial fibrillation (on coumadin) was found to have a few beats of idioventricular rhythm on an Ekg done for an insurance exam. Resting EKG is normal, a 24 hour Holter revealed occasional PVB's and one 5 beat run of VT. A stress echo demonstrated normal LV function and no inducible ischemia. The LA was slightly enlarged and there was moderate MR. A signal average EKG was normal. Electrolytes are normal The pt is asx Comments about management would be welcome.
GEORITTER - 09:08pm Apr 27, 2006 (#15 of 17)
Add to 'My Discussions' | Post to this topic
To me using the information furnished, I think you have done a masterful job in patient care. I would not change a thing. If the parox AF is trouble some then a beta blocker (or CCB) will probably control the rate satisfactorily. Obviously, close follow-up is needed because these type of patients develop new stuff , unexpectedly.
SKOUFIS - 11:40pm Apr 27, 2006 (#16 of 17)
Add to 'My Discussions' | Post to this topic
the problem with the strategy of rate control and anticoagulation is that as patients get older they have more and more occasions per year when they need to come off coumadin temporarily for various reasons, such as needing some elective surgery, needing a biopsy, developing anemia and then awaiting workup, developing an ulcer and then needing to be off for x number of weeks, etc. During these intervals they are at risk for stroke. Maybe during a clinical trial of only two or three years duration these people can be admitted to the hospital and placed on heparin every time this comes up but in our community this would not be practical. Therefore I do try to maintain sinus rhythm with amio for as long as possible.
GEORITTER - 06:48pm Apr 28, 2006 (#17 of 17)
Add to 'My Discussions' | Post to this topic
this is an interesting philosphy. Tell us about your amio side effect percentage. Mine has been over 50% with a few serious ones. This is on 200 mgm daily. Life is hazardous and although we may reduce its hazards with medication, we cannot eliminate it. For me the hazards were less off the drug unless it was no alternative.
