Thyroid UK
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Levo and blood pressure

Hi, i started taking levothyroxine 25mcg about 4 weeks ago. My blood pressure is now above range 160/80 it was 20 to 30 points lower before, I take losartan potassium 100mg and felodipine 10mg to control my hypertension and it has been stable for the last 10 years. I am concerned my gp may see this as a reason to stop treating my underactive thyroid tsh 5.7 at last blood test sorry no referrence range. Any thought appreciated.

3 Replies

I think the problem is your low dose of 25mcg. Too low a dose can backfire and make us feel worse. Usually 50mcg is a starting with 25mcg increases every six weeks till you feel well (not till your blood reaches somewhere in range). Now you are on levo he/she shouldn't stop it. I shall give you a couple of links and read about FT3 and FT4 on the first one:-

Maybe you should give GP a copy of the one below :)


Thanks Shaws those links may indeed be useful. My GP readily admits his knowledge is limited, I actually see this as a good sign if he is open to improve his knowledge as we go. As I am over 60 the 25mcg initial dose is within prescribing guidlines and as long as it gets increased as subsequent blood tests indicate I am happy to wait. Thanks Keith.


Although I didn't experiment much with the timings, I found Felodipine taken an hour after Levothyroxine would leave me very sleepy, but there's no problem when it's taken four or more hours after. I don't think it had much of an effect on my blood pressure until a diuretic was added. It may be the cause of my shoulder and hip pain and weakness -- preliminary tests for myopathy have drawn a blank.


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