When I take a thyroxine tablet in the morning, on my empty stomach, my blood sugar rises around 30Mg/dL. I’ve tested it many times now and have commented to my doctor about it, but she doesn’t seem to believe what I’m saying.
I test before I take the tablet and then again about an hour afterwards and each time I have had almost the exact same rise in blood sugar.
Does anyone else have the same problem?
You know, since I don’t like eating right away when I wake up, I take my thyroxine first thing in the morning… and then after 30min to an hour or so, I will eat… I find I can’t eat as many carbs in the morning anymore, and have always attributed it to insulin resistance, but it may well be the thyroxine… I know others have shared how they have had higher blood sugar once they got placed in this therapy, so I hope they share some of what they went through. 
I’ve kept a check on it for months now… I am often up around 4 am checking my blood sugar, so if I don’t have a low I’ll take it then when I’m up… I know that I’ll have an empty stomach then… However, when I check an hour after my blood sugar is always up.
Sometimes if I don’t wake up at 4 am, I’ll take my Thyroxine at 6.00 when the alarm goes off, I do the same then, first check my blood sugar, which is usally between 80 and 100, and every time I check an hour later, my blood sugar has gone up 30.
So I’m pretty confident it’s the pill and not the ‘Dawn syndrome’! x
My thyroid med- Drop me like a Rock.
You know what yours do to you! Even if the Dr. treats you like you don’t and claims “that just cant be”
I had that problem until my dose increased. Really. I felt like 25 mcg made me insulin resistant but 50 mcg didn’t have that same effect. That sounds crazy, I know.
Maria
I’ve asked this question on another TuD discussion. Most people reported an increase in insulin doses with thyroid supplementation. My endo agrees this is true, but didn’t give me a reason why.
Hi Gerri… that’s great, at least I know I’m not the only one this happens to and who is questioning it… Maybe they don’t give the answer because they don’t know and they think they’d lose face if they said they didn’t know why… I would sooner someone tell me I’m sorry I don’t know, but I will find out… than not bothering to reply… or just say a simple I’m sorry I don’t know why… but they don’t and they won’t. x
I found this online…
“If you have diabetes, it is a good idea to check your blood sugar more often when starting or stopping levothyroxine (or when changing your dose), as the medication can affect your blood sugar levels.” http://endocrine-system.emedtv.com/levothyroxine/precautions-and-warnings-with-levothyroxine.html
I have emails sent to me from a group called iguard… They tell you if there could be a clash between medicines. You put in all your medication and it evaluates the danger levels and tells you which ones are likely to cause a reaction. It did also warn me to watch out for a rise in blood sugar as a very uncommon side effect when taking Thyroxine with diabetes medications.
It alerted me to watch for the signs. x
It’s one of those “because I said so” things, a non-answer. Annoying!
Hi -
Do you take novalog or humalog? I take humalog and just started taking synthroid last Friday, and by glucose readings have been out of control. I figured that I would just need to increase my dosage, but it seems that the problem is more that the insulin is MUCH slower acting (i need to take it very far ahead of eating, so every time I eat, I’ve been skyrocketing). Also, I’ve always had ‘dawn syndrome’/ my count rise a little in the morning even though I don’t eat, but now it seems to be amplified! I’m thinking of changing to novalog to see if maybe it won’t interact so bad w/ the synthroid.
I don’t think this is true AT ALL… I’ve been running hyper for the past few months and my BG has been insane. It was worse before my meds were lowered but I am still hyper and running higher BG’s than I’d like to.
I also noticed an immediate increase in insulin needs when I went to the original high (incorrect) dosage… all of my insulin needs went up 50%. I don’t think that’s coincidence since it has NOT gone away.
I agree with Sarah. I’ve experienced the same with insulin increasing by about 50% also. Getting thyroid levels correct helps with BG control, but at the cost of more insulin.
Hi SS, No unfortunately, I’m on the NPH mix of Novalin… I get lots of swings from low to high… going to see if they can change me onto something else soon. When they first found out I had diabetes, the doctor lowered my Thyroxine tablets because he said that it reacted with the metformin. But since I moved to the USA, they’ve put it back up and also increased my metformin intake… so I don’t know if it’s the Thyroxine reacting to the metformin or not… However, it really doesn’t matter when I take my Thyroxine in the early hours of the morning… after I take it, my blood sugar always rises… I’ve tested it many times now so I know it has to do with the Thyroxine and not with the dawn effect. At least on me anyhow. I’m not disputing it’s different with other people, we all have a different body make-up so drugs can’t be expected to affect us all in the same way.
I’ve never really thought of what reaction the Thyroxine has with the Novalin though, or if it has a reaction at all. I’ll need to look that one up and see.
I have the same problem as you though with the sugar going high after meals, even with the addition of metformin (which I don’t think is doing much to help). I go pretty high after breakfast but stabilise after lunch because the effects of the nph kick in then and sometimes go too far… if I don’t fill up on carbs then I go really low. and then I get the swing effect. So you can’t win whatever you do…lol.
Good luck with getting sorted out SS. x
Yes, I get a BG spike right after I take the pill; I’m just now trying to figure out what to do about it. The first thing I’m going to try is bolusing for 15g of carbs before I take my pill (i’m on a pump). My total daily insulin is already up 25% overall, and I bet it will end up higher than that. My doctor denies any of this is connected to levothyroxine; I guess it’s not in the literature. But I can repeat the results, and I can document them.
I posted a link earlier today to another discussion… but yes, this is in the counter indications for medications… that it can affect blood sugar levels… It’s just that, well… a pharmacist would probably know that, instead. It’s kind of shocking how many docs don’t seem to know that.
“Diabetes patients - Synthroid may affect your blood sugar. Check blood sugar levels closely. Ask your doctor before you change the dose of your diabetes medicine.”
Read more: http://www.drugs.com/cdi/synthroid.html#ixzz0nkEnqJwQ
My insulin increased a lot when I began thyroid supplementation.