hypothyroidism after breast cancer treatment?

[dasa29]

Breast cancer chemotherapy completed in feb 24, never had any problems with thyroid but now my tsh is 35 t4 is 9, on levothyroxine 75mcg but the symptoms r really kicking my butt.. fatigue, weight gain, no energy for anything… continuing with immunotherapy and oncologist not sure whether that is causing the thyroid problems… any ideas?

[PurpleNails Administrator]

A TSH of 35 is very high and your FT4 low. Always add lab range as ranges vary. That would make anyone very tired & unwell, you are likely struggling more as dealing with treatment.

Were you started on 75mcg? Standard starting dose is 50mcg. Some manage on a higher starting dose but often it’s a shock to the system causing greater symptoms.

It’s usually to retest every 6weeks & increase dose by 25mcg per day. Most are optimal when TSH is under 2, (around 1) & importantly FT4 In upper 3rd of range and the active FT3 is in top 50% of range. Improvements can be gradual with thyroid, & with other health concerns it will be difficult to pinpoint what is responsible for which symptom.

NHS Often go by TSH & do not always complete a full test. Many use private companies to do DIY fingerprick tests via post to gain a complete picture.

Optimal Nutrients are important to ensure good conversion to FT3, Have you had folate,ferritin, b12 & vitamin D tested during your treatment?

[dasa29 in reply to PurpleNails]

I was put on 50mcg to start with early September where tsh was 32 and t4 12, increase to 75 mcg couple of weeks ago where tsh was 35 and t4 9…

[SlowDragon Administrator]

yes treatment for breast cancer can increase risk of developing hypothyroidism

palomahealth.com/learn/brea...

tsh is 35 t4 is 9, on levothyroxine 75mcg

How long have you been on 75mcg dose levothyroxine

Were you on this BEFORE test results above…..or was dose increased to 75mcg after these results

Bloods should be retested 6-8 weeks after each dose change or brand change in levothyroxine

For full Thyroid evaluation you need TSH, FT4 and FT3 tested

Also both TPO and TG thyroid antibodies tested at least once to see if your hypothyroidism is autoimmune……though more likely result of your cancer treatment

Very important to test vitamin D, folate, ferritin and B12 at least once year minimum

Low vitamin levels are extremely common when hypothyroid,

About 90% of primary hypothyroidism is autoimmune thyroid disease, usually diagnosed by high TPO and/or high TG thyroid antibodies

Autoimmune thyroid disease with goitre is Hashimoto’s

Autoimmune thyroid disease without goitre is Ord’s thyroiditis.

Both are autoimmune and generally called Hashimoto’s.

Significant minority of Hashimoto’s patients only have high TG antibodies (thyroglobulin)

NHS only tests TG antibodies if TPO are high

20% of autoimmune thyroid patients never have high thyroid antibodies and ultrasound scan of thyroid can get diagnosis

In U.K. medics hardly ever refer to autoimmune thyroid disease as Hashimoto’s (or Ord’s thyroiditis)

Essential to test vitamin D, folate, ferritin and B12

Lower vitamin levels more common as we get older

For good conversion of Ft4 (levothyroxine) to Ft3 (active hormone) we must maintain GOOD vitamin levels

What vitamin supplements are you taking

VERY important to test TSH, Ft4 and Ft3 together

Recommended that all thyroid blood tests early morning, ideally just before 9am, only drink water between waking and test and last dose levothyroxine 24 hours before test

This gives highest TSH, lowest FT4 and most consistent results. (Patient to patient tip)

Private tests are available as NHS currently rarely tests Ft3 or all relevant vitamins

Post all about what time of day to test

healthunlocked.com/thyroidu...

Testing options and includes money off codes for private testing

thyroiduk.org/testing/

Medichecks Thyroid plus BOTH TPO and TG antibodies and vitamins

medichecks.com/products/adv...

Blue Horizon Thyroid Premium Gold includes BOTH TPO and TG antibodies, cortisol and vitamins

bluehorizonbloodtests.co.uk...

Medichecks and BH also offer private blood draw at clinic near you, or private nurse to your own home…..for an extra fee

Only do private testing early Monday or Tuesday morning.

Tips on how to do DIY finger prick test

support.medichecks.com/hc/e...

[dasa29 in reply to SlowDragon]

Thank u for the detailed reply, I’ll have a read up

[SlowDragon Administrator in reply to dasa29]

What brand was 50mcg

Which brand for 75mcg

Many people find Levothyroxine brands are not interchangeable.

Most easily available (and often most easily tolerated) are Mercury Pharma or Accord

Mercury Pharma make 25mcg, 50mcg and 100mcg tablets 

Mercury Pharma also boxed as Eltroxin. Both often listed by company name on pharmacy database - Advanz

Accord only make 50mcg and 100mcg tablets. Accord is also boxed as Almus via Boots, 

Wockhardt is very well tolerated, but only available in 25mcg tablets. Some people remain on Wockhardt, taking their daily dose as a number of tablets 

July 2024

Crescent levothyroxine. Dosages: 12.5, 25, 50, 75, 100

(Not yet known if all approved dosages are or will be available).

Excipients: lactose monohydrate, maize starch, croscarmellose sodium, gelatin and magnesium stearate.

Lactose free brands - currently Vencamil or Teva

Vencamil is lactose free and mannitol free. originally only available as 100mcg only, but 25mcg, 50mcg and 75mcg tablets became available Sept 2024

Prior to March 2023 Vencamil was called Aristo

How to get Vencamil stocked at your local pharmacy

healthunlocked.com/thyroidu...

Posts discussing Vencamil

healthunlocked.com/thyroidu...

healthunlocked.com/thyroidu....

Teva makes 12.5mcg 25mcg, 50mcg, 75mcg and 100mcg

Many patients do NOT get on well with Teva brand of Levothyroxine.

Teva is lactose free, but contains mannitol as a filler instead of lactose, which seems to be possible cause of problems. Mannitol seems to upset many people, it changes gut biome 

Helpful post about Teva

healthunlocked.com/thyroidu...

Posts that mention Teva

healthunlocked.com/search/p...

Teva poll

healthunlocked.com/thyroidu...

Helpful post about different brands

healthunlocked.com/thyroidu...

List of different brands available in U.K.

thyroiduk.org/if-you-are-hy...

Once you find a brand that suits you, best to make sure to only get that one at each prescription.

Watch out for brand change when dose is increased or at repeat prescription.

Government guidelines for GP in support of patients if you find it difficult/impossible to change brands

gov.uk/drug-safety-update/l...

If a patient reports persistent symptoms when switching between different levothyroxine tablet formulations, consider consistently prescribing a specific product known to be well tolerated by the patient.

academic.oup.com/jcem/artic...

Physicians should: 1) alert patients that preparations may be switched at the pharmacy; 2) encourage patients to ask to remain on the same preparation at every pharmacy refill; and 3) make sure patients understand the need to have their TSH retested and the potential for dosing readjusted every time their LT4 preparation is switched (18).

And here

pharmacymagazine.co.uk/clin...

Discussed here too

healthunlocked.com/thyroidu...

[SlowDragon Administrator]

Levothyroxine is an extremely fussy hormone and should always be taken on an empty stomach and then nothing apart from water for at least an hour after

Many people take Levothyroxine soon after waking, but it may be more convenient and perhaps more effective taken at bedtime

verywellhealth.com/best-tim...

markvanderpump.co.uk/blog/p...

markvanderpump.co.uk/blog/p...

No other medication or supplements at same as Levothyroxine, leave at least 2 hour gap.

Some like iron, calcium, magnesium, HRT, omeprazole or vitamin D should be four hours away

(Time gap doesn't apply to Vitamin D mouth spray)

If you normally take levothyroxine at bedtime/in night ...adjust timings as follows prior to blood test

If testing Monday morning, delay Saturday evening dose levothyroxine until Sunday morning. Delay Sunday evening dose levothyroxine until after blood test on Monday morning. Take Monday evening dose levothyroxine as per normal

[serenfach]

Did you have a contrast medium with an MRI at any point? This contains iodine, and some people cannot handle it. This is rare, but the reaction to the iodine can upset the thyroid, sometimes shutting it down. This is just a thought, and may not be applicable to you, but it could give you a clue...

I hope they get your dose sorted - it takes a while, but you will get there and feel more human!