I would sit down and look carefully at the actual ingredients list. Some medications have sugars (of some sort) in them or in their coating. I was looking at the list for Gaviscon (liquid suspension) last night, had to do it online as I no longer take it (used to have it on repeat prescription). Way down the list was mention of saccharine (with a chemical name following). As some people can react to saccharine this was worthy of note.
It must be said that a change in routine, alcohol intake and weather may have skewed your figures.