Pentasa, Asacol & Salofalk are all the same drug. The difference is the format and where it delivers the medication in the GI tract. I believe it is just a brand name difference. To the best of my knowledge Asacol & Salofalk are formulated to break down at the end of of the small intestine delivering medication to the terminal ileum and beyond (ceceum, colon etc). It shouldn't be an issue, however you should call your nurse to confirm.