I Have To Have A Colonoscopy On Thurs And I

I have to have a colonoscopy on thurs and I just got the split dose prep stuff and my instruction include to not take anything with iron and I can't find that answer for methimazole and I take hydrochlorot for water behind inner ear and some say that is a high blood pressure med and the instructions say to not take high blood pressure meds. can you answer for those?