Article - liver damage caused by levothyroxine / liothyronine excipients

[asidist]

Unfortunately haven’t had a chance to get on here much the past 2-3 weeks nor to fully digest this article but I wanted to share the link as it was jarring to come across and I think people would want to be cognizant of this. Much of the terminology/ abbreviations were above my head, particularly on a quick read, so would love if someone with a better grasp of it could post take-aways, especially if there are particular inactive ingredients we need to be cautious of. Thanks.

journals.lww.com/cmj/fullte...

[Hidden]

I cannot pretend to understand it, especially when it says "In 1986, Shibata et al[2] reported that triiodothyronine (4 months) and levothyroxine (4 days) caused liver damage in a patient".Very confusing when levothyroxine is synthetic and triidothyronine is natural.

[Nanaedake]

It seems to be saying that because levothyroxine is drawn into and processed in the liver that the molecules it is bonded to in manufacture, which are subsequently drawn into the liver as a result of the attachment or bond, can cause liver damage.In particular Fe2o3 which seems to be iron oxide or ferric oxide? It says its very rare for this to happen.

It's interesting though because it might happen more than is realised, just not picked up on. It just shows what a complex and difficult medicine levothyroxine is to manufacture and difficult to monitor the end result in humans. And perhaps explains why not all levothyroxines suit everyone.

[helvella Administrator Thyroid UK]

Fascinating and, potentially, very helpful.

I found the typography absolutely dire - very difficult to follow. So I copied it all into a Word document, laid it out a little better (in my opinion!), then saved it as a PDF. Which is here:

dropbox.com/s/vpohizfvdare3...

I note in particular this:

Recently, liver damage caused by levothyroxine tablets containing different additives has been reported. Per Toki et al,[5] liver damage may be caused by levothyroxine tablets containing Fe2O3.

Although it has often been said that levothyroxine and iron compounds react, form a complex, and effectively reduce the levothyroxine that can be absorbed, this liver damage issue is new to me.

If it is as I read it, could this be an extra reason to separate consumption of food from levothyroxine ingestion. (As a reassurance, I don't think any UK levothyroxine products contain iron oxides!)

[Gophe]

I just read this. It involves a single patient who suffered liver damage on one type of levothyroxine (produced by Merck, called 'LTA' in the article) but was okay when switched to a second type (produced by Berlin Chemie, called 'LTB' in the article).

It says: ' Since the main component of LTA and LTB is levothyroxine, their differences arise from their different additives. LTA additives are corn starch, gelatin, lactose, and stearic acid magnesium, while those of LTB are calcium bicarbonate, dextrin, long-chain glycerate, sodium carboxymethyl starch, and microcrystalline cellulose. Corn starch, gelatin, lactose, and stearic acid magnesium may have caused liver injury after considering RUCAM evaluation.

It then reports a finding from another study also related to additives, as helvella notes above, that found iron(III) oxide in levothyroxine may also cause liver damage.