If you are alleric to potatoes, does that mean you would be alleric to potatoes starchs in medicanc?

Probable: Usually one is allergic to the protein portion of a food and thus if all of the protein has been removed, the product is likely safe. However how does one find out especially when it is prepared by different manufacturers. I suggest that you consult an allergist to verify that you do have a potato allergy (rare) and consider an oral challenge test to potato starch to see if you can tolerate it.