Reformulation of thyroxine tablets is not as ea... - Thyroid UK

Thyroid UK

140,948 members166,084 posts

Reformulation of thyroxine tablets is not as easy as it looks

diogenes profile image
diogenesRemembering
5 Replies

The makers of Euthyrox T4 tablets decided to reformulate and put outa paper justifying this as being accurate as regards bioequivalence, The article is as below. I know well that many posters on TUK complain about practical non-equivalence of reformulated tablets. We have submitted a Letter to the Editor regarding the best mathematical/statistical way of analysing this data. When the data is properly statstically handled, the comparison at the individual level shows far from a close relationship (almost random). This should help other reformulators to consider the optimum statistical analysis in producing their results. The obvious solution is to keep to one formulation by one producer if at all possible.

Curr Med Res Opin. 2017 Feb;33(2):169-174. doi: 10.1080/03007995.2016.1246434. Epub 2016 Oct 21.

New levothyroxine formulation meeting 95-105% specification over the whole shelf-life: results from two pharmacokinetic trials.

Written by
diogenes profile image
diogenes
Remembering
To view profiles and participate in discussions please or .
Read more about...
5 Replies
helvella profile image
helvellaAdministrator

I am holding my breath waiting to read your letter! :-)

In that paper, it says:

The new formulation will enable patients to receive a dose fine tuned to their medical needs, contributing to improved safety in the use of L-T4.

ncbi.nlm.nih.gov/pubmed/277...

I cannot see what they could do to the product to improve the fine tuning of the dose that was not possible with the (claimed) bio-equivalent previous formulation.

If the products are 100% bio-equivalent, there would be absolutely NO change in how well tuned the dose.

It is only if they are NOT bio-equivalent that there would be any reason to mention the fine tuning of the dose.

Nanaedake profile image
Nanaedake

Oh, how I wish the NHS would recognise the need to stick to one formulation instead of dispensaries being allowed to switch 'brand' at the whim of the contracted pharmaceutical supplier!

I don't object to generics and I think the cost of essential drugs needs to be kept to a minimum. However, historically, different levothyroxines have been found to be unequivalent in potency effect once ingested.

hjh88 profile image
hjh88

That’s so interesting. I just tried some Euthyrox last month for the first time, only for a couple of weeks, and became horribly hypo very quickly. I’d always read on here that folk got on with it quite well generally so was surprised when I didn’t but a reformulation would explain that. Such a shame as it seems to be a bit of a go to for those needing to self medicate!

jgelliss profile image
jgelliss

Diogenes thank you for your heads up posts as always . It's very appreciated . This is unbelievable . The only thing that thyroid companies ought to do is to remove fillers that we can do without and dyes from the thyroid meds.

If it's Not Broke . Why Fix. The only reason I can read into their reformulating is to save more money for themselves . In my book that called *Greed*.I don't believe for one second that their fix is for our benefits . I'm very worried that when one thyroid brand changes the other brands will follow suit too. This happened all across with the NDT brands too. I for one I smell a rat . I don't want to be the lab rat for the thyroid companies. I hope something can be done to stop this from happening .

Herhat profile image
Herhat

I had been taking the original formulation of Euthyrox with the lactose base for over 10 years, but since I started on the new citric acid formulation in November 2019 I have not felt the same. My thyroid levels has been checked and are corect, but I just feel constantly washed out, exhausted. My specialist just tells me to give it time.

Not what you're looking for?

You may also like...

Switching formulations (and sources) for T4 is not the easy thing that it appears to be

We have a short paper coming out very soon in Clinical Phamacokinetics...
diogenes profile image
Remembering

It is "levothyroxine" - not "Synthroid"

And it is liothyronine not Cytomel! Drug names In the research literature drugs are not...
helvella profile image
Administrator

Study examining liquid/soft gel T4 therapy against solid tablets

This study has concentrated on bioequivalaence of soft gel and liquid T4 formulations but also...
diogenes profile image
Remembering

CYSTIC FIBROSIS AS A CAUSE OF MALABSORPTION AND INCREASED REQUIREMENT OF L-THYROXINE

In case we have anyone with cystic fibrosis, or responsibility for someone, this paper which...
helvella profile image
Administrator

is it safe to take spirulina tablets with either levothyroxine, t3 or ndt?

i just bought some spirulina tablets ( 500mg) and took 6 of them. got them from holland and barrat....

Moderation team

See all
PurpleNails profile image
PurpleNailsAdministrator
helvella profile image
helvellaAdministrator
SlowDragon profile image
SlowDragonAdministrator

Content on HealthUnlocked does not replace the relationship between you and doctors or other healthcare professionals nor the advice you receive from them.

Never delay seeking advice or dialling emergency services because of something that you have read on HealthUnlocked.