Occurrence of thyroxine tablet (Thyradin S(®)) - induced liver dysfunction in a patient with subclinical hypothyroidism.

[helvella]

This levothyroxine issue centres on a difference between dosages! Identical except for Iron(III) oxide or ferric oxide is the inorganic compound with the formula Fe2O3. Also known as rust!

Occurrence of thyroxine tablet (Thyradin S(®)) - induced liver dysfunction in a patient with subclinical hypothyroidism.

Kang S, Amino N, Kudo T, Nishihara E, Ito M, Hirokawa M, Miyauchi A, Tamada D, Yasuda T

Endocrine Journal, 19 May 2015, 62(8):719-724

doi.org/10.1507/endocrj.ej1... PMID: 25994001

Abstract

A 54-year-old woman with subclinical hypothyroidism developed liver dysfunction after increasing dose of levothyroxine (L-T4) in tablet form (Thyradin S(®)) from 25μg to 50μg. Viral hepatitis, autoimmune hepatitis and NASH were ruled out with examinations. After cessation of levothyroxine in 50μg tablet form, liver enzymes gradually returned to normal. She was diagnosed levothyroxine-induced liver injury, based on criteria proposed in DDW-J 2004 workshop. Thyradin S(®) powder 0.01% (here in after referred to as L-T4 in powder form) was tried as an alternative, and liver enzymes have remained within normal range. As for Thyradin S(®) tablet, additives are different for each type of levothyroxine sodium content. The difference of additive is whether Fe2O3 is contained or not: it is not included in Thyradin S(®) 50μg tablet and powder form. Although there are two case reports in the Japanese literature and three case reports in the English literature of liver dysfunction suspected due to L-T4, we cannot find past reports about cases of drug induced liver dysfunction due to Fe2O3 free levothyroxine tablet form. This is a rare case report of drug induced liver injury due to Fe2O3 free levothyroxine tablet form, and administration of L-T4 in powder form may be useful for treatment of cases similar to this one.

Abstract accessible at link below but some onward links are to Japanese language sites which are difficult to use:

europepmc.org/article/MED/2...

See also:

Liver injury induced by levothyroxine tablets in a patient with hypothyroidism

healthunlocked.com/thyroidu...

Liver Injury Induced by Levothyroxine in a Patient with Primary Hypothyroidism

healthunlocked.com/thyroidu...

[Regenallotment Ambassador]

is this just in this product or a wider concern with Levo? I’ve not seen anything about this before. 🤔

[helvella in reply to Regenallotment]

As I read it, it could apply to any levothyroxine which contains ferric oxide. But few, if any, others do so. Certainly no UK products which are all white.

It did make me consider Roma 20 microgram Liothyronine capsules. But they differ in the Active Pharmaceutical Ingredient. The Yellow Iron Oxide (E 172) they contain is confusing. Other sources say that Yellow Iron Oxide is ferric oxide hydroxide whereas the ferric oxide in the Thyradin S is red. At least one, possibly two, significant differences. Plus, being contained in the gelatin might tend to keep the API and the ferric oxide somewhat separate.

[Regenallotment Ambassador in reply to helvella]

Your knowledge is quite astounding! Thanks 🍄

[helvella in reply to Regenallotment]

I'm just quite reasonable at looking things up! Don't confuse that with me knowing anything.