yeah you need to relax and take the time to organize your thoughts.
loperamide does cross the blood/brain barrier though in a much smaller concentration compared to binding in the gut. in fact, in order for PGP to export loperamide (which it does), loperamide would first have to cross this barrier to be a sufficient PGP substrate.
loperamide does not 'block' opiates, it just has a high affinity / low threshold and taking massive amounts of it can easily build a tolerance to receptors all over your body. much like methadone doesn't block, it is just strong.
i also suggest using the search engine to save time and a talkin' to, especially if its regarding the 1649th loperamide post.