Curious about lethothyroxine tablets - their appearance

[DawnD]

I was watching Elementary the other night and Sherlock Holmes opened a small pill bottle and tipped out some tablets, which were bluish capsules, and he said that they were lethothyroxine. My thyroxine tablets have always been small white tablets, whichever strength they were (i.e. 25mcg, 50mcg or 100mcg). So it made me wonder whether it was because Elementary is set in America and that the tablets are different there?

[RedApple Administrator]

I haven't seen the programme, so can't be sure. But yes, in the US levothyroxine comes in various forms and tablets tend to be coloured according to dose, as in the pictures of US brands Levoxyl and Synthroid on this page for example:

perinatology.com/Reference/...

(Pics are about half way down the page)

[DawnD in reply to RedApple]

Thank you!

[helvella Administrator]

Have a look here:

synthroid-levothyroxine.blo...

(Ironic it is a .uk site!)

You can see that Synthroid is coloured according to dosage. You can also see that there are some 12 dosages! I suspect that the large the range of dosages has driven the need to make them different by colour.

The 50 microgram dosage of most (possibly all) USA levothyroxine products has no colour and is white. It is not unheard of for people to take their entire doses as 50 microgram tablets in order to avoid the colourants.

Problem is, you said "capsules". Hmm. Well some levothyroxine is produced in capsule-shaped tablets:

drugs.com/imprints/137-gg-3...

Some USA product is indeed in capsule form - but I can't find a photograph!

Without knowing the context, I don't know if the search for a blue capsule form has to extend into Canada, Mexico and beyond!

For reference, from the Synthroid Prescribing Information document:

Strength (mcg) - Color additive(s)

25 - FD&C Yellow No. 6 Aluminum Lake*

50 - None

75 - FD&C Red No. 40 Aluminum Lake, FD&C Blue No. 2 Aluminum Lake

88 - FD&C Blue No. 1 Aluminum Lake, FD&C Yellow No. 6 Aluminum Lake*, D&C Yellow No. 10, Aluminum Lake

100 - D&C Yellow No. 10 Aluminum Lake, FD&C Yellow No. 6 Aluminum Lake*

112 - D&C Red No. 27 & 30 Aluminum Lake

125 - FD&C Yellow No. 6 Aluminum Lake*, FD&C Red No. 40 Aluminum Lake, FD&C Blue No. 1, Aluminum Lake

137 - FD&C Blue No. 1 Aluminum Lake

150 - FD&C Blue No. 2 Aluminum Lake

175 - FD&C Blue No. 1 Aluminum Lake, D&C Red No. 27 & 30 Aluminum Lake

200 - FD&C Red No. 40 Aluminum Lake

300 - D&C Yellow No. 10 Aluminum Lake, FD&C Yellow No. 6 Aluminum Lake*, FD&C Blue No. 1, Aluminum Lake

rxabbvie.com/pdf/synthroid.pdf

Rod

[DawnD in reply to helvella]

Thank you both for the replies. It seems to be "over the top" with the different amount of tablets! Although if those were prescribed I would only need to take 1 tablet a day instead of 4! (I'm on 175mcg at the moment so take 3 x 50mcg and 1 x 25mcg). When I was on 112.5mcg I had to alternate 100mcg one day and 125mcg the next. Odd that they are all colour-coded as every one of mine has been white!

[helvella Administrator in reply to DawnD]

Oh yes - all UK thyroid hormone tablets are white.

The range of doses seems to suggest a problem with USAians performing simple arithmetic.

But, as you rightly say, if on long-term, stable dose, a single tablet is very appealing. And it avoids mixing different formulations.

Rod