Thyroid and antihistamine

[AppleOrchard]

I’m due a blood test on Thursday morning. I take my meds at night. I take an antihistamine as well. How long in advance of the blood test should I stop taking the antihistamine?

Thank you very much.

[annnsandell]

I have not heard of Antihistamine affecting results but as I take one at least all summer, it would be interesting to see this reply.

[AppleOrchard in reply to annnsandell]

Hopefully someone will know the answer!

[Buddy195 Administrator]

You shouldn’t take an antihistamine if you are having tests for allergies as antihistamine can affect the results of a skin test. However,I’m not aware that you should stop taking them prior to a thyroid or vitamin blood test. I always take a daily antihistamine in the summer months.

[PurpleNails Administrator]

I take anti histamine and never heard it affects thyroid results.

Only high doses of Biotin (B7) are know to skew results. Check supplements labels.

Levo shouldn’t be taken at the same time as other medication. It’s a very fussy hormone. So you might want to alter timings if you are taking at same time,best to leave at least a 2 hour gap.

Usually morning doses are advised to be delayed until after draw. Don’t know what the advice is with night time doses.

I’m not certain but I’m sure I’ve read to split the dose so half taken as normal and the rest after draw. I may have read this as advise regarding lio, not levo so you may get accurate answers if you repost focusing on timings before test.