Can a change in Levothyroxine brand cause symptoms?

[Franzen]

Hi - New to this forum. Has anyone experienced new symptoms when changing brands of Levothyroxine? I was given a different brand during lockdown (I guess supply issues) and started to feel some strange symptoms a month or so ago - having been previously stable for years. Along with a recurrence or some thyroid symptoms I’ve previously experienced (thinning hair, low libido, dry skin) I have developed really worrying nerve symptoms in my arms and hands (numbness, tingling, feelings of heat, pain, loss of coordination and slow movements). I’ve been referred to a neurologist for those symptoms who is going to do MRI and nerve conduction tests but it’s occurred to me that this could actually all be thyroid related. I’m getting thyroid bloods done today by my GP (they were normal in February before I changed meds) - but wondered if anyone else had experienced something like this? It’s pretty disconcerting to have to really concentrate to tie your shoes!

[liaratsoni]

Hi there and welcome!

It is generally recommended to stay on the same brand of levo as people can react differently to different brands and there might be variances in potency/fillers that could affect your absorption or levels. Some people can also react badly to fillers in tablets: a prolific example is that many on this forum have huge issues with the TEVA brand of levo - I am one such person and for me it gave me horrendous nausea and continual burping so bad I couldn't lay down at night to sleep! So it is definitely possible that a chnage in brand could have affected you! Hope this is helpful

[Franzen in reply to liaratsoni]

Hello. Thanks for such a quick reply! I’ve just checked and the brand I was changed to in lockdown was Teva. Very interesting to hear that others have had issues with that brand. I’m normally on Actavis (and am back on that now). I’m hoping the hand/arm nerve symptoms are thyroid related as some of the other things they could be are a little bit scary!

[liaratsoni in reply to Franzen]

The forum did a poll on TEVA and side effects and I believe some people mentioned nerve symptoms:

healthunlocked.com/thyroidu...

I personally have also experienced strange and frightening sensations in arms too when I am hypo - I get periods where feel like I am disconnected from the muscles in my arms and legs and that I am not fully in control of them or they feel strange so your definitely not alone there! Very frightening but very likely just related to your thyroid and should be OK once you've been back on your old brand for a time

[Franzen in reply to liaratsoni]

That’s good to know - thanks! Yes my hands feel like they respond really slowly when I ask them to do something. Unloading the dishwasher in the morning seems like a massive challenge. Thanks for your input. Will follow through with all of the tests the neurologist recommended to rule out anything more sinister - but reading this and the thread you linked to, it seems very likely that it’s either side effects of the TEVA or I am hypo due to change in the meds.

[SlowDragon Administrator]

Yes

Which brand of levothyroxine were you on and which brand of levothyroxine were you given recently

How much levothyroxine are you currently taking and when were levels last tested....

Symptoms can be due to being under medicated and in need of dose increase too

Many people find Levothyroxine brands are not interchangeable.

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.

Many patients do NOT get on well with Teva brand of Levothyroxine. Teva contains mannitol as a filler, which seems to be possible cause of problems. Teva is the only brand that makes 75mcg tablet. So if avoiding Teva for 75mcg dose ask for 25mcg to add to 50mcg or just extra 50mcg tablets to cut in half

Teva and Aristo are the only lactose free tablets

healthunlocked.com/thyroidu...

Teva poll

healthunlocked.com/thyroidu...

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).

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...

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)

[Franzen in reply to SlowDragon]

Hi. Thanks very much for all of this info. I had been switched to Teva (50 micrograms) so it sounds like that could well be the problem (actually reading the poll thread I think I probably had some other Teva side effects (like extreme nausea) that I’d blamed on a new contraceptive pill). Last had levels checked in February prior to the switch. Have had bloods taken today - so let’s see what they come back with. I have been back on Actavis for 8 days so fingers crossed things will start to calm down as that gets back into my system. Thanks very much everyone.

[SlowDragon Administrator in reply to Franzen]

Standard starter dose of levothyroxine is 50mcg (unless over 65 years old).

Bloods should be retested 6-8 weeks after each dose increase

Dose increased up as fast as possible

The aim of Levothyroxine is to increase the dose slowly in 25mcg steps upwards until TSH is under 2 (many patients need TSH significantly under one) and most important is that FT4 is in top third of range and FT3 at least half way through range

Bloods should be retested 6-8 weeks after each dose increase

What were your test results from before starting on levothyroxine

Have you had thyroid antibodies tested

NHS guidelines on Levothyroxine including that most patients eventually need somewhere between 100mcg and 200mcg Levothyroxine.

nhs.uk/medicines/levothyrox...

Also note what foods to avoid (eg recommended to avoid calcium rich foods at least four hours from taking Levo)

Important to regularly retest vitamin D, folate , ferritin and B12 as these are often very low when hypothyroid and frequently need supplementing to maintain optimal levels

Always take levothyroxine on empty stomach and then nothing apart from water for at least an hour after