Amiodarone is not NICE

As has been pointed out (pointedly) to DrRich, we do not have death panels in the United States. And indeed, considering that we’re not conducting military tribunals for Islamist terrorists who have tried (or succeeded in) killing and maiming as many of us as possible, it seems relatively unlikely that we’d assemble death panels (which sound even less due-process-friendly than military tribunals) for American patients.

What we will have, however, is a federally-mandated assembly, body, committee, commission, board, diet, parliament, or posse (but not a panel) of experts which will carefully evaluate all the objective clinical evidence regarding a particular medical treatment, and make “recommendations” to doctors about whether or when to use that treatment. The model which frequently has been offered up for our consideration, as we contemplate the workings of such a non-death-panel, is the British National Institute for Clinical Excellence, or NICE.

This being the case, it might be instructive to examine the preliminary decision made by NICE last week to disallow the use of the new antiarrhythmic drug, dronedarone (Multaq, Sanofi-Aventis) for British patients with atrial fibrillation (AF). Dronedarone is a long-awaited drug, painfully developed and tested over a very long period of time, as a potential replacement for the drug amiodarone (which, despite its many drawbacks, is the most commonly prescribed antiarrhythmic drug for AF).

AF is a common heart rhythm disturbance in the elderly and in patients with underlying heart disease. It can cause palpitations, dizziness, poor exercise tolerance and – because blood clots tend to form in fibrillating atria – often leads to stroke. Unfortunately, the antiarrhythmic drugs that are used to treat AF are either incompletely effective, or have potentially dangerous side effects, or both.

Indeed, as a group, antiarrhythmic drugs tend to be only moderately effective, and are toxic and poorly tolerated. Worse, one of the very nasty side effects sported by most antiarrhythmic drugs is the propensity to produce (paradoxically), sudden death from cardiac arrhythmias – a phenomenon we electrophysiologists like to call “proarrhythmia,” since this seems a less unnerving term than “sudden death.”

The reason amiodarone has become the most commonly used antiarrhythmic drug for AF is that it is measurably more effective than any of the other drugs, and better yet, tends not to cause proarrhythmia.

However, if Satan had wanted to invent an antiarrhythmic drug, he would have invented amiodarone. There are at least three features of amiodarone that render it diabolical.

First, as mentioned, the drug is obviously far more effective than other antiarrhythmic drugs, and does not cause proarrhythmia. So on its face, like most entrapping vices, it spins a certain appeal, one that lures doctors into using it far more blithely than they should.

Second, amiodarone has bizarre pharmacokinetics. Before it becomes fully effective, amiodarone needs to completely saturate the tissues of the body. During this “loading period,” which is generally several weeks in duration, large doses are typically used. Once the drug is deemed to be loaded, a relatively small daily maintenance dose can be used. This is because amiodarone is not excreted from the body like most drugs are, by the kidneys or the liver. Instead, amiodarone likes to stay in the cells “forever,” and for practical purposes you get rid of it only through the normal shedding of your body’s cells, such as skin cells and gut cells. This means that once you are loaded with the stuff, it’s a part of you for a long, long time – just about forever. (Amiodarone can still be detected in the blood for at least a year after the last dose.) Once you are on amiodarone, you’re on it.

And third, amiodarone has a unique and disturbing toxicity profile. Because it is stored in essentially every organ of the body, its side effects can affect almost any organ. And because amiodarone continues accumulating in your body as long as you continue taking it, the side effects can develop weeks, months, or even years after you begin the stuff. The side effects of amiodarone are almost too numerous to describe, but some of the more unique ones include:

• Amiodarone commonly causes deposits to form on the cornea – often leading to “halo-vision,” where looking at bright lights at night is like looking at the moon on a foggy evening.
• Amiodarone can cause a very striking and quite disfiguring blue-grey discoloration of the skin, generally in parts of the body exposed to the sun, producing an appearance which has been unkindly termed “Smurf syndrome.”
• Amiodarone often greatly sensitizes the skin to sunlight, so that even trivial exposure can cause a nasty sunburn.
• Amiodarone often causes thyroid disorders, both hypothyroidism (low thyroid) and hyperthyroidism (high thyroid). These thyroid problems are common with amiodarone, can be unusually difficult to recognize and treat, and are often disabling and even dangerous.
• Amiodarone can cause neuropathy of the peripheral nerves, and more disturbingly, significant ataxia (a severe gait disturbance and loss of balance).
• But the most serious side effect of amiodarone is pulmonary toxicity – lung disease. This can take several forms, from an acute respiratory distress syndrome that makes patients desperately ill, requires intensive care, and often results in death, to a more insidious, gradual, unnoticeable, “stiffening” of the lungs that both the doctor and patient can overlook until finally severe and irreversible lung damage is done.

And of course, given the drug’s extremely long excretion period, if any of these side effects should occur (and one or more of them occur in at least 25 – 30% of people who take the drug), you may be living with them (if indeed you remain alive) for quite a while.

As you can see, Beelzebub would be very proud.

When DrRich was a practicing electrophysiologist, his rule was to offer amiodarone only if the arrhythmia being treated was life-threatening or very disabling or disruptive to the patient’s life, and for which there were no other reasonable therapies, and only after a long, long talk about the potential risks. He has always been distressed that many of his cardiology colleagues appear to prescribe it so readily.

In any case it is no wonder that a substitute for amiodarone has been long sought – a drug that is as effective as amiodarone, that still has minimal proarrhythmia, and does not have the bizarre toxicity profile of amiodarone.

For years, hope has been high for dronedarone, whose chemical structure is very similar to amiodarone’s. As it turns out, however, dronedarone is an imperfect substitute. While the new drug appears to have amiodarone’s low proarrhythmia potential, and while it thankfully has none of amiodarone’s unique side effects (and indeed, appears to be quite well tolerated), dronedarone is not as effective as amiodarone.

Still, it has a decided advantage over amiodarone (much less toxicity) and over other antiarrhythmic drugs (low proarrhythmia), so in many patients who have AF it seems like it might be worth a try. It might not be effective in as many patients as amiodarone, but for those patients in whom it is effective, well, it’s effective. And if it doesn’t work well enough, you can always switch to something else.

Indeed, that’s how antiarrhythmic drugs ought to be used most of the time. Pick a drug that seems to provide the best available balance between effectiveness and side effects for a given patient and try it. If it is ineffective or causes problems, stop it and move to the next one. The more antiarrhythmic drugs that are available, the better the chance of eventually finding an adequate choice for your patient. (It is worth pointing our that once you try amiodarone, however, you are done with this trial-and-error strategy – once you are on amiodarone, you are, for practical purposes, always on amiodarone.) In any case, the appropriate choice of an antiarrhythmic drug, as in many areas of medicine, can only be made on an individual basis, and not on a population basis.

But alas, this is not how a Clinical Effectiveness Tribunal like NICE works. These Diets of Medical Quality will only look at the average response to a therapy within a population of patients and, seeing (for instance) that dronedarone may only treat 40% of AF patients effectively while amiodarone treats 60%, will deem dronedarone to be insufficiently effective to justify its additional expense. (Read NICE’s “appraisal document” on dronedarone for yourself.) NICE has determined that amiodarone is a suitable choice for the treatment of atrial fibrillation, and that there is no need for a drug like dronedarone (or, presumably, any new drug that trades a bit of efficacy for a toxicity profile that is much less extravagant than that of amiodarone).

Old-fashioned physicians like DrRich, who might reason, “An initial trial of dronedarone would likely spare 40% of my AF patients from having to be exposed to the horrific toxicities of amiodarone, so perhaps it’s worth a try,” are hopelessly and irredeemably of low quality, and aren’t worth bothering over.

And as for the Smurfs and Smurfettes on amiodarone, despite their breathing difficulties, unsteady gaits, inability to see at night, and severe skin photosensitivities which preclude their Florida or Arizona vacations, at least their anguish over not being allowed a viable and available alternative will be temporary. For the drug companies, seeing how a Posse of Clinical Excellence operates, will take the only logical business step remaining to them and severely curtail their development of drugs aimed at offering incremental improvements over the current choices.

There will be no alternatives to agonize over, and everyone will be happy. This, DrRich thinks, is the plan.