Can thyroid levels change when on medication?

[cakelover75]

Hello,

I'm hoping some of the thyroid experts on here can advise me.

I was diagnosed with an underactive thyroid after the birth of my daughter almost 5 years ago. I was put on 150mcg of levothyroxine and all was fine. About a year ago, my dosage was decreased to 125mcg (my gp was always trying to decrease it before this even though I felt fine and didn't want to cut the dosage but after this time, I went along with it).

For the past 5-6 weeks now, I have felt very sluggish, sore throat, constipated, basically what I feel are some signs that my thyroid is underactive again. Can levels change like that? I am going to see my dr tomorrow and ask for my blood levels to be checked again.

[Pleasemrstweedie]

Yes they can. On Levo you are looking for a TSH at the bottom if the range and FT4 and FT3 in the top 25% of their ranges.

Get re-tested, ask for an increase and in future refuse a reduction if you feel well.

Is your doctor dosing by TSH by any chance?

[Shinyshoes2]

I could have written that post OP
my gp has also lowered my dose from 150g thyroxine to 125mg cos my levels were 0.01 ( they should be between 1 and 5 )
I don't know what all this means but I too feel crap, sluggish , lack of energy , lack of motivation, spaghetti brain , sleeping like a log, very very heavy and for long periods of time, hand numbing and pins and needles
It's shit, it's been 3 weeks since they lowered my dosage, I'm due a retest after 8 weeks, I'm going to push for one sooner, I can't feel like this for another 5 weeks, my work is suffering and my dp is losing patience with my lack of ' get up and go '

[ErrolTheDragon]

My DH has Hashimoto's thyroiditis and his levels change. I think the way it works in this particular sort is that it's an autoimmune disease - there can be flare-ups of activity of the remaining thyroid (during which he needs to temporarily reduce his dose else it kicks off his atrial fibrillation - there really can be a balancing act with thyroxin dose to avoid this) - and then afterwards it becomes less active so he has to have a slightly higher dose than before.

[cakelover75]

Thank you all for your replies. I don't know what method my Dr is dosing by Pleasemrstweedie, but she is usually good at running thorough tests on my bloods. She is always trying to reduce my medication though as if weaning me off it will make me better or something .
Thanks for the info about what levels to look for, I have looked at the more lengthy thyroid threads but they are very in-depth and I find all the information hard to follow.

Hope you get your dosage sorted too Shinyshoes2.

[sanfairyanne]

have you seen the actual reference range, as mine is well below 1, something like 0.3. if you are definitely below the range, then take in a copy of 'understanding thyroid disorders' and show your gp the part where it says some people need their tsh to be suppressed. also check your t4 and t3 results and show the gp they are still in range (doesnt really matter what tsh says as long as t4/t3 are in range).
150mcg is an entirely normal dose

[Clarella]

You've said in title when on medication - which medication? As yes, I've found some can. Lots of things interact with thyroxine. Also, iron levels (and b12/ folate and vit d) are very important too. Not iron test though, ferritin specifically.

Sertaline definitely requires a dose increase, grapefruit reduces effectiveness by 10%.

As posted below, Tsh is best 1-0.3 (if you feel ok like this) and t4 (sbd t3 if you can get em to do it, more so lab than gp) should be upper ref range.

Always test in the morning, take your thyroxine after the test (or not the night before if at night) in order to get a base line as they all change slightly during the day.

Definitely get the book mentioned below, by Dr Antony toft, bmj publication. It clearly says 'keep Tsh low!'

[Clarella]

I'm convinced cocodamol does something funny to my thyroxine, and benylin. Been quite unwell in past and now avoid.

[Clarella]

Most t4 is converted to t3 in liver so I guess anything affecting liver could in theory affect thyroxine, as well as anything affecting digestion could too.

[cakelover75]

Hello, thanks again for all your replies. Clarella, by "medication", I meant levothyroxine, should've made that more clear.

I went to see my Dr yesterday and she did a blood test herself (am always referred on to the practice nurse for tests) so at least she took me seriously and she gave me a 2 month prescription for Vitamin D. I'm really hoping she increases my medication again and leaves it as is. I had always thought 150mcg was a high dose as well sanfairyanne. The worst part of it is - my Dr also has an underactive thyroid so you'd think she'd be more understanding !

[Clarella]

I'm on 150 and have a friend on 175, and a colleague on 300. It's weight related.

Lots of things can affect it and sadly the actual pills aren't always trusty, the TEVA brand was withdrawn in 2012 for being faulty (I was on a faulty batch when pregnant caused all sorts of issues )

Various medicines can cause an issue with absorption and some people say you need more in the winter. However your symptoms could be due to vit d, iron etc.