I have just been diagnosed with an under-active thyroid and have started the process in getting my medication right. But i also suffer from severe heart burn and have been on omeprazole for two years. When i questioned a nurse about this medication cancelling out the other i was told that as long as there was half hour between taking the medication then it would be fine. But two separate chemists have told me that it should be more than four hours. Who do i believe. Even the warnings that come with the medication say no to omeprazole but are you not supposed to believe your doctors and nurses. Help !!!