Long term diagnosed - recent meds adjustment

Hi everyone. I've had under active thyroid for a long time, 10-15 years, but recently was told my levels of T4 had dropped so they upped my dosage from 100 to 125 levothyroxine. I have been taking the higher dose for 6 days and for 5 days I've been feeling unwell. Very lightheaded, like I'm drunk but of course am not, and hot, mainly in my head and sometimes I've felt like my pulse is racing and I have shallow breathing. It's hard to explain. I wonder if it's because I'm trying to get used to the new dose of meds. Also, I haven't been told how to take the meds properly, ie on an empty stomach with no other meds half an hour before anything including caffeine. I'm now doing this so wonder if the cumulative effect of that and the extra dose is why I'm feeling ill.

Please help! πŸ™‚ Will it settle down soon? Has anyone else experienced this? I know it takes weeks to get used to a dose and feel better. But I hope I'm not feeling like this for weeks!

Thanks πŸ™‚

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Has the brand changed? Sometimes the pharmacist struggles to give you the correct dose so ends up using two brands. You might be reacting to a new preparation?

Hi Cwill. It's certainly worth checking that. Thanks, I'll check now πŸ™‚


The patient information leaflet which comes with Levothyroxine should mention avoiding taking Levothyroxine with food and drink.

If you were previously taking Levothyroxine with coffee, breakfast or with other meds absorption would have been reduced and you may be feeling unwell because you are absorbing better plus had a dose increase. You could revert to your previous dose for a couple of weeks to see whether the symptoms improve and then try 100/125mcg alternate days for a couple of weeks before increasing to 125mcg.

Hi Clutter. That's great advice thanks very much. I've looked at the info leaflet and it does advise that. It's because I've been on it so long I don't check that anymore. Your on the same wave length as me; I thought there may be a cumulative effect. Thanks again


I think the PIL underestimates how long should be left between Levothyroxine and food/drink, meds and supplements. For maximum absorption Levothyroxine should be taken with water 1 hour before, or 2 hours after, food and drink, 2 hours away from other medication and supplements, and 4 hours away from calcium, iron, vitamin D supplements, magnesium and oestrogen.

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