? About liothyronine side effects.

[Mggirl]

So my dr. Increased my dosage of lio to 20 mcg and I have been on increased dosage for 10 days. I feel good but I have noticed that my bowel movements have slowed down. I normally have a movement every day but since the increased dosage it's more like every 3 days it seems weird to me especially because I feel so much better. Is that a side effect when starting a new dose of liothyronine?

[SlowDragon Administrator]

Looking at previous posts you are currently only taking tiny 25mcg dose of levothyroxine

Is that correct?

Hardly surprising that you feel under medicated

Taking almost any dose of T3 will completely suppress your own thyroid output

If just on levothyroxine, a full replacement dose is typically 1.6mcg per kilo of your weight. So unless, extremely petite, that’s likely to be at least 100mcg levothyroxine per day

If conversion of levothyroxine to Ft3 is poor, then small doses of T3 added alongside levothyroxine. Sometimes Levothyroxine is reduced by 12.5mcg or 25mcg when T3 is added.

If just being prescribed T3, with no levothyroxine, most patients would need 40-60mcg T3. Sometimes higher

Currently your being prescribed T3 that has shut your own thyroid down, but not on anywhere near high enough dose of levothyroxine or T3

[Mggirl in reply to SlowDragon]

Yes the dose of 25mcg Levothyroxine is correct and the 20mcg of lio is a dose increase of 10mcg my dr will do labs in 6 weeks along with the vitamin test. I do feel better so it’s at least a step in the right direction getting her to increase the dose has been a slow process because she doesn’t have any experience with Hashimotos patients. She feels like I need to see a Endo but there are none in my area so she is working on finding me one in a area that’s 8 hours away and maybe I can have one in person visit and any other app virtually.

[SlowDragon Administrator in reply to Mggirl]

So you very likely need next dose increase in levothyroxine

guidelines on dose when on just levothyroxine... by weight

Even if we don’t start on full replacement dose, most people need to increase levothyroxine dose slowly upwards in 25mcg steps (retesting 6-8 weeks after each increase) until on full replacement dose

NICE guidelines on full replacement dose

nice.org.uk/guidance/ng145/...

1.3.6

Consider starting levothyroxine at a dosage of 1.6 micrograms per kilogram of body weight per day (rounded to the nearest 25 micrograms) for adults under 65 with primary hypothyroidism and no history of cardiovascular disease.

gp-update.co.uk/Latest-Upda...

Traditionally we have tended to start patients on a low dose of levothyroxine and titrate it up over a period of months. RCT evidence suggests that for the majority of patients this is not necessary and may waste resources.

For patients aged >60y or with ischaemic heart disease, start levothyroxine at 25–50μg daily and titrate up every 3 to 6 weeks as tolerated.

For ALL other patients start at full replacement dose. For most this will equate to 1.6 μg/kg/day (approximately 100μg for a 60kg woman and 125μg for a 75kg man).

If you are starting treatment for subclinical hypothyroidism, this article advises starting at a dose close to the full treatment dose on the basis that it is difficult to assess symptom response unless a therapeutic dose has been trialled.

A small Dutch double-blind cross-over study (ArchIntMed 2010;170:1996) demonstrated that night time rather than morning dosing improved TSH suppression and free T4 measurements, but made no difference to subjective wellbeing. It is reasonable to take levothyroxine at night rather than in the morning, especially for individuals who do not eat late at night.

BMJ also clear on dose required

bmj.com/content/368/bmj.m41

bestpractice.bmj.com/topics...

[Mggirl in reply to SlowDragon]

Ok, I will get back with you in a month with new test results. Thank you so much for all your help I feel like I have been walking in circles for a long time and now I’m finally on the right path.

[SlowDragon Administrator in reply to Mggirl]

Including vitamin tests too

What vitamin supplements are you currently taking?

[SlowDragon Administrator]

Obviously all four vitamins need to be regularly tested and supplement to optimal levels

When were vitamin D, folate, B12 and ferritin last tested?

What vitamin supplements are you currently taking