FPIES (Food Protein-Induced Enterocolitis Syndrome) is a non-IgE mediated response to proteins. We have an infant that has had classic severe acute FPIES reaction to poultry. In addition, every food and oral medicine has provoked some reaction (ranging from inconsolable crying to violent vomiting and persistent diarrhea). Some vomiting (outside the 2-4h typical FPIES) occurred immediately and some was as delayed as 12 h. Are these symptoms consistent with chronic FPIES? or is FPIES only part of the answer?
My nephew had FPIES, he is also IgA deficient & has general food sensitivities & my looking into seems to indicate that these things are linked simply meaning that having FPIES does have some influence on an increase in having other food sensitivities (as well as being IgA deficient). You may want to have your child tested for IgA deficiency if that hasn't been done yet as it's also linked to other potential issues. None of it is terribly scary things, but things you want to be aware of nonetheless. IgA deficiency is actually relatively common, effecting about 1 in 500 people.
I do not recall her mentioning him reacting to medication, but he could have & I just wasn't told or don't recall her saying it. I can also tell you there are FPIES groups on facebook that are there for support & to bounce questions specifically off those living with it or who have lived with it.
This link here about halfway down pretty much says you can have a FPIES reaction to anything, depending on the severity of the case & the potential for trace amounts of irritants in the ingested food. I am sure medication could fall under that as fillers and binders can contain a number of ingredients & they aren't even always spelled out of they are considered no allergenic & GRAS.