I'm doing a barium swallow ct scan. can i take my prevacid (lansoprazole) or is a ppi a contradiction?

Ask your doc.: Clarify this with your doctor. With many tests, instructions about taking current meds on the day of testing should be addressed. Check any pre-test instructions you may have received. Or ask the radiology department for the answer (they can contact your doc, too, if there is a question about taking them or not).

Probably not: If the ordering physician has not provided instructions for avoiding PPI before the procedure, you can take your medicine.