How is the starting dose of Levo determined?

Hi, I was just recently prescribed Levothyroxine at 100 mcg a day. My last TSH was 5.96. The first Endo that I saw almost started me on a 25 dose when TSH was like 5.25 and then she consulted with an Endo who specializes in bone and they decided not to. If those Drs had a problem with a 25 dose then wouldnt a 100 mcg a day be too high? Im 44 yrs old and very overweight. I don't know if that factors in, but I assume it does in configuring dosages.

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  • Normally, no matter what your TSH (mine was 100), the starting dose is 50mcg with a blood test after six weeks approx with a rise of 25mcg thereafter about every six weeks until you feel well (but most doctors only take notice of the TSH and may stop increases when you are somewhere in the 'range'). The aim should be a TSH of around 1 or lower.

    When you go for your next blood test leave about 24 hours between your dose of levo and the test and take it afterwards. Also fast (you can drink water). The appointment should be as early as possible.

    100mcg of Levo is quite a high starting dose and our body has to get used to taking replacement thyroid hormones.

    If GP hasn't tested Vitamin B12, Vit D, iron, ferritin and folate ask for these to be done too as we are usually deficient.

  • I do know that Vitamin D is lil lower than 30, but he acted like that was typical for this area or something, can't remember exactly. Thanks for the advice, it's very helpful!

  • Jean, Weight is sometimes used to calculate starting dose in thyroidectomised patients but dose thereafter is adjusted according to thyroid levels. Generally the starting dose is calculated according to thyroid levels and age and heart health.

    Patients <50 years without heart disease can be started on a replacement dose of 75-100mcg. Patients >50 are more likely to be started on 25-50mcg, and patients with heart disease on 25mcg. Doctors do vary in their prescribing with some being much more cautious than others. When the starting dose is very low it will take months to get on an optimal dose.

    You should have a follow up blood test in 6-8 weeks. Arrange an early morning blood draw and fast, water only, as TSH is highest early and falls post-prandially. Take Levothyroxine after the blood draw. If you are overmedicated on 100mcg it will be reduced.

    For maximum absorption Levothyroxine should be taken with water one hour before food and drink, or two hours after, 2 hours away from other medication and supplements, and 4 hours away from calcium, vitamin D, iron and oestrogen.

    ____________________________________________________________________________________

    I am not a medical professional and this information is not intended to be a substitute for medical guidance from your own doctor. Please check with your personal physician before applying any of these suggestions.

  • I just started taking it today on an empty stomach with water etc., but wondered if I should break it in half and take twice a day? Thanks!

  • Jean43, there's no advantage in doing that and the disadvantage is keeping multi-doses away from food etc. Levothyroxine is a storage hormone replacement and takes 7-10 days to be absorbed when it will convert to T3 as required. It'll take up to 6-8 weeks to feel the full impact of the dose but you should feel improvement during that time. Symptoms may lag behind good thyroid levels by another 6-8 weeks.

    _________________________________________________________________________

    I am not a medical professional and this information is not intended to be a substitute for medical guidance from your own doctor. Please check with your personal physician before applying any of these suggestions.

  • Hello i would start lower than 100mcg i started on 125mcg my tsh was over 40 and it was awful my body went into shock i started getting muscle spasms in my arms my heart raced felt hyped up i soon dropped too 50mcg and built up slowly i would speak too doctor again im very over weight myself and i still needed too start small and work up. Good luck with getting the care you require

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