my question is there any drug intereaction between cardizem cd and taking following herbal laxative blend 250mgs Slippery elm bark, peppermint leaf, black walnut bark,Chinese skullcap root extract, Cascara sagrada bark extract & senna leaf extract, it's Health Resources Advanced Colon Care it's re my father whos 90yrs old miralax isn't helping as well as milk of mag?