for those who are not aware, do not take ferrous fumarate for at least 2 hours after taking levothyroxine as it can decrease the effects, and the amount of levo your body intakes!
I was prescribed ferrous fumarate, and started taking it along with all my other meds on the morning. and only found this out by chance when my chemist asked to do a spot check qeustionare on my meds! and was surprised i didnt know this. there are other meds to aviod also when taking levothyroxine and i would advise people to check on this as you dont always get told these things. I have also been taking Cimetidine for a while which can also block the effects of levo so its no wonder the doctor has upped my dose!
Hope this info is useful to some of you.
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J_angel
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Ooooo thank you I had no idea and have recently started multivitamin that include above take it with breakfast after levothyroxine about an hour after! Will experiment before seeing doc on fri see if helps, thank you lots!!! Was wondering whether the Concerta I've just started is causing problems too?! x
It isn't only ferrous fumarate, but also sulphate, ferrous gluconate and every other iron supplement. That includes iron-fortified cereals like Special K.
The time gap is also sometimes suggested to be four hours as two hours does not guarantee a sufficient physical separation.
Levothyroxine binds strongly to iron compounds to form a complex. Once the complex has formed it simply passes through and can never be absorbed.
There are many substances which interfere with absorption which is why the only safe advice is to try to take levothyroxine away from food, drink (other than water), supplements and other medicines. For example, calcium containing medicines such as ant-acids.
Some people find taking levothyroxine at bed-time is beneficial and might help to avoid clashes. This poll has a lot of discussion - there are both positive and negative views:
The Patient Information Leaflet for Mercury Pharma Eltroxin 25 mcg says this:
Taking other medicines:
Please tell your doctor or pharmacist if you are taking or have recently taken any other medicines, including medicines obtained without a prescription, especially if you are taking:
• digoxin, used to treat heart problems including an irregular heart beat
• insulin and other treatments for diabetes
• colestyramine and colestipol, used to reduce the level of cholesterol in the blood
• calcium supplements, used to treat low levels of calcium in your blood
• antacids, used to treat indigestion
• rifampicin, used to treat infections
• iron preparations, used to treat anaemia
• cimetidine, used to treat excess acid in the stomach
• beta-blockers (e.g. propranolol) used to treat high blood pressure
• drugs used to treat epilepsy (e.g. phenytoin, carbamazepine, primidone, barbiturates)
• anticoagulants (e.g. warfarin) used to thin the blood and treat blood clots
• drugs used to treat depression and other conditions, including amitriptyline, imipramine and sertraline
• oral contraceptives (“the pill”)
• steroids and other hormone treatments such as male hormone replacement therapies
• anti-inflammatory drugs e.g. phenylbutazone and aspirin
• decongestant medicines such as phenylephrine, or adrenaline (for treatment of severe allergies)
• imatinib, used for the treatment of cancer
• sodium polystyrene sulfonate, used in the treatment of kidney failure
• sucralfate, used for the treatment of gut ulcers
• ketamine, used as an anaesthetic.
The PILs for the other UK levothyroxine products have similar statements.
I don't think that you can safely assume that any medicine not appearing in that list is safe to take with levothyroxine - as in, at the same time.
For a start, at least one make of enalapril contains maize starch, crospovidone, pregelatinised statch and iron oxide. Lack of a major adverse effect does not mean that there will not be a relatively minor effect on absorption that could still be significant.
If it is possible sensibly and safely to make sure there is a gap of a couple of hours between them, that might ensure no interference at all.
You are in a difficult place because while you should be able to ask a pharmacist, I am not convinced that all pharmacists are capable of providing accurate advice. Nevertheless, I think that is what you should do.
Note please that I most certainly cannot advise at all on this issue as I simply do not have the knowledge to do so.
Thank you Rod for your reply. I will speak to my pharmacist when I can catch him - he is my age and tends not to be there all the time now!
The main problem is one of logistics. I now take my meds at 5am so that I can have breakfast and vit D at 7-7.30 and off to work at 8am., sucking B12 as I drive!
AD-Cal, a calcium+ Vitamin D supplement says on instructions to wait 4 hrs after Thyroxine. Years ago Ipicked up the iron thing and cursed all the jokers who put extras in breakfast cereal. Organic cornflakes were ok.
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