Good Evening, I have been on a high slow release morphine dose 400mg x 2 in 24 hours. I took a Piriton allergy pill the other evening and noticed that my tolerance to the morphine was very much affected and my feet had swollen up in the morning and have very slowly been going down 5 days now, I leave indentations if I press quite hard. I imagine that I cannot take both of these medications together? Thank you in advance.