Thursday, June 06, 2013

Iodine: The love-hate relationship

As an endocrinologist, I don't usually have patient situations so dire that I fear for their lives. Sure, I'm frequently involved in sick patients, the post-cardiac surgical patients or the trauma patients who are steps away from death. But my patients, people I play a direct role over?
Yesterday was one such day. I hesitantly put her in harm's way, and referred her to see a surgeon- she was quoted a 10% chance of mortality in the OR. It was an extreme case of amiodarone-induced thyrotoxicosis.
As you know, about a third of amiodarone is iodine. Iodine is the substrate from which the thyroid gland produces thyroxine and triiodothyronine. As such, any exposure to high concentrations of iodine may induce hyperthyroidism (and hypothyroidism, but that's a different story) by means of an exaggerated Jod-Basedow phenomenon (also called type 1 Amiodarone induced hyperthyroidism) or thyroiditis (type 2).
Mrs. J was a 60-something woman with a history of hypertrophic cardiomyopathy, complicated by atrial fibrillation and other tachyarrhythmias. And so not surprisingly her cardiologist put her on Amiodarone in an attempt to tame the heart. After a year, her cardiac status did not get better- she kept going in and out of the hospital for congestive heart failure. During one such visit, she was found to be markedly hyperthyroid.
Her Amiodarone stopped prior to her visit to her. When I saw her, despite having been off this for 2 months, and having been on maximal methimazole therapy, her free T4 was above the upper limit of measurement for our lab (above 6), her free T3 was 12. Her levels were worse than they were the month before. And despite calcium channel and beta blockade her heart was ticking away at 120 beats a minute.
And so, this was a situation all endocrinologists hate. What the heck do I do?
The temporal sequence makes type 2 AIT unlikely, as thyroiditis is expected to have at least improved two months later. So we are likely dealing with type 1. You might consider the conventional therapeutic options for hyperthyroidism: antithyroid medications to slow down production of new hormone, radioactive iodine ablation or thyroidectomy. Unfortunately the norms don't apply here.
Because by the time you see them, the gland is already supersaturated with iodine from the Amiodarone, antithyroid medications have very little effect. Likewise, radioactive iodine will not work- one would simply pee out the I131 you administer. Which leaves you with surgery. But you'd need to find a gutsy (crazy) surgeon and anesthesiologist who would take a severely thyrotoxic patient to the OR.
You could wait it out, but the halflife of Amiodarone is 100 days, and it may take upwards of 10 months before they become euthyroid. Many patients can't wait that long. Mrs. J was one of them. Her cardiologist was nervous she was going to go into some fatal tachyarrhythmia, or die of congestive heart failure, if we did nothing.
Which takes us to yesterday. We admitted her a couple of days before the planned surgery to have a better hold of things. She spent some nights in the ICU, but on the day of surgery despite maximal doses of Esmolol, she remained tachycardic. But she remained strong-willed, and keen to have surgery. Despite the odds given by the surgeon, she was ready to proceed.
I saw her a few minutes before they wheeled her to the OR. She was in a room full of family, most of whom were in tears. Her husband held on to her, crying, worried this was the last time he'd see her alive.
I held her hand and told her she was in good hands- she had a good surgeon working on her- though deep in my heart I hated that we had no other option but surgery (some have published case reports suggesting plasmapheresis to perhaps be beneficial- but data is weak). I wasn't sure I would be able to forgive myself should something bad happen to her.
I came home from work worried and distracted. However at 3 PM, I got the call- she sailed through surgery and was in recovery. It was a big burden off my shoulder, and what a relief it was. I saw her before I started clinic today, and despite the JP drain in her neck, she gave me a hug.
But this was a reminder to me of what a challenge Amiodarone-induced thyrotoxicosis is to treat. As good as a medication it is, the truth is us endos have a love-hate relationship with this medication.

12 Comments:

Blogger huajern said...

Interesting patient.
Luckily I haven't seen such a bad case of amoidarone-induced thyrotoxicosis yet. How often is it so severe?

12:04 PM  
Blogger vagus said...

I see about 1-2 of these a year. Of course, anecdotally isn't a good representation since I'm after all a thyroid specialist and there is a referral bias.
That being said, this patient had the perfect storm as he was not only hyperthyroid, but also had hypertrophic cardiomyopathy with bad hemodynamics so we had to be aggressive with surgery

1:24 PM  
Blogger Saiful said...

We've used Potassium Perchlorate in these cases along with effective doses of Neomercazole of at least 60mg daily.

6:11 PM  
Blogger vagus said...

I believe Neomercazole is a prodrug, converted to Methimazole which is exactly what we used.
Potassium Perchlorate isn't available here, but works by blocking uptake of iodine- kinda like Methimazole. So, in cases like AIT where the thyroid is already laden with iodine I doubt both of these are very effective.
Also I didn't add that our patient was starting to develop agranucytosis- presumably this is an adverse event also possible with Neomercazole.

7:38 AM  
Anonymous Anonymous said...

I just wondered why the cardiologist did not monitor the thyroid hormone levels when the patient was placed on amiodarone. I am sure LIVER function tests were carried out?

11:39 PM  
Blogger 艾丰 said...

jianbin1214
fitflops shoes
fitflops sale
fitflops sale clearance
fitflops sale
fitflops shoes
michael kors outlet
michael kors outlet
michael kors outlet
tiffany and co
tiffany jewellery
beats by dr dre
beats by dre
oakley sunglasses
oakley sunglasses
ray-ban sunglasses
ray ban sunglasses
hollister uk
lululemon outlet
ugg outlet
ugg boots
ugg boots
rolex watches
mulberry handbags
mulberry bags
mulberry outlet
mulberry sale
mulberry handbags
mulberry handbags
louis vuitton handbags
louis vuitton handbags
toms shoes
omega watches
ferragamo shoes

8:45 PM  
Blogger ninest123 said...

ninest123 16.02
ray ban sunglasses, replica watches, tory burch outlet, nike air max, michael kors, tiffany and co, oakley sunglasses, michael kors outlet, nike air max, polo ralph lauren outlet, louis vuitton, ugg boots, replica watches, uggs on sale, tiffany jewelry, oakley sunglasses, longchamp outlet, prada handbags, louboutin shoes, prada outlet, michael kors outlet, nike free, louboutin outlet, louis vuitton outlet, longchamp outlet, michael kors outlet, chanel handbags, ugg boots, ugg boots, burberry, oakley sunglasses, louis vuitton, burberry outlet online, ray ban sunglasses, michael kors outlet, ugg boots, nike outlet, polo ralph lauren outlet, ray ban sunglasses, louboutin, michael kors outlet, oakley sunglasses, cheap oakley sunglasses, louis vuitton, jordan shoes, longchamp, gucci outlet, christian louboutin outlet, louis vuitton outlet

10:01 PM  
Blogger ninest123 said...

ray ban pas cher, ralph lauren uk, michael kors, vans pas cher, oakley pas cher, true religion outlet, air force, nike free run uk, true religion jeans, nike air max, nike free, sac guess, converse pas cher, mulberry, coach outlet, nike roshe run, timberland, nike roshe, north face, tn pas cher, burberry, lacoste pas cher, coach purses, north face, michael kors, longchamp, hollister pas cher, new balance pas cher, ralph lauren pas cher, nike blazer, hermes, true religion jeans, air max, michael kors, longchamp pas cher, louboutin pas cher, nike air max, lululemon, abercrombie and fitch, vanessa bruno, air jordan pas cher, hogan, sac longchamp, michael kors, hollister, replica handbags, true religion jeans, nike huarache, ray ban uk, nike trainers, nike air max

10:46 PM  
Blogger ninest123 said...

iphone 6s plus cases, abercrombie and fitch, bottega veneta, north face outlet, ray ban, vans, valentino shoes, wedding dresses, nike air max, chi flat iron, timberland boots, mcm handbags, nfl jerseys, converse, celine handbags, ghd, giuseppe zanotti, hollister, s5 cases, nike roshe, north face outlet, vans shoes, nike air max, mont blanc, instyler, babyliss, iphone 5s cases, p90x workout, gucci, soccer jerseys, iphone 6s cases, oakley, ferragamo shoes, lululemon, iphone 6 cases, ralph lauren, beats by dre, birkin bag, louboutin, herve leger, iphone 6 plus cases, reebok shoes, baseball bats, new balance, hollister, soccer shoes, asics running shoes, iphone cases, ipad cases, mac cosmetics, jimmy choo shoes, insanity workout

10:49 PM  
Blogger ninest123 said...

links of london, louis vuitton, moncler, pandora charms, toms shoes, canada goose uk, louis vuitton, canada goose, pandora jewelry, ugg,ugg australia,ugg italia, converse outlet, sac louis vuitton pas cher, swarovski crystal, canada goose, canada goose, pandora jewelry, replica watches, moncler, hollister, barbour, ugg boots uk, karen millen, moncler, juicy couture outlet, moncler, marc jacobs, wedding dresses, doudoune canada goose, barbour jackets, doke gabbana outlet, moncler, canada goose, supra shoes, pandora charms, bottes ugg, louis vuitton, louis vuitton, thomas sabo, swarovski, moncler, moncler, juicy couture outlet, coach outlet, moncler outlet, canada goose outlet, montre pas cher, lancel, canada goose outlet, ugg pas cher, ugg,uggs,uggs canada
ninest123 16.02

10:52 PM  
Blogger Zheng junxai5 said...

zhengjx20160607
ralph lauren outlet
kate spade handbags
cheap air jordans
retro 11
michael kors outlet clearance
nike outlet
nike sb janoski
cheap jerseys
air jordan shoes
timberlands
coach outlet store online
montblanc pens
coach factory outlet
ray ban sunglasses
jordan shoes
cheap toms
oakley sunglasses
christian louboutin outlet
nike outlet store
ray ban outlet
coach outlet clearance
michael kors outlet online
polo ralph lauren
ralph lauren
nike air max 90
hollister clothing store
michael kors outlet clearance
true religion sale
cheap ray ban sunglasses
kate spade handbags
michael kors purses
supra footwear
coach outlet
nike free uk
hollister clearance
louboutin shoes
gucci outlet
coach outlet
kids lebron shoes
coach outlet

10:35 PM  
Blogger xjd7410@gmail.com said...

christian louboutin shoes
gucci outlet
ray ban outlet
michael kors handbags
oakley sunglasses
toms
nike air max
nike air max
michael kors outlet online sale
nike outlet
nike huarache shoes
christian louboutin outlet
basketball shoes
ghd hair straighteners
michael kors outlet online sale
nike blazers
louis vuitton handbags
coach outlet store online
adidas shoes
oakley sunglasses
jordan 8s
louis vuitton
rolex submariner
louis vuitton
mont blanc pens
christian louboutin shoes
michael kors handbags
christian louboutin sale
christian louboutin outlet
louboutin pas cher
ray ban sunglasses
kobe bryant shoes
adidas ultra boost
timberland outlet
polo ralph lauren outlet
nike outlet store
nfl jerseys wholesale
adidas uk
hollister clothing store
nike air huarache
2016.7.7haungqin

2:58 AM  

Post a Comment

<< Home