Antibiotics and Nausea

Question on the nausea. My husband has been on Babesia treatment for 5 months now and has tolerated it well. Mepron, azithromician, Bactrim and Nystatin. Also takes probiotics daily and has reduced sugar and dairy intake. Recently he has had nausea that seems to be daily now. Is this normal with antibiotic treatment to always feel nausea. No other issues going on and has had more "better" days since stating treatment. Most of original symptoms have subsided, night sweats, cold extreme worries, muscle spasms, brain fog, confusion etc.

Just worried now that antibiotics are having a negative affect on his stomach. Is there something I need to watch out for?

Has been on all for the whole time nothing new added. And no hasn't been checked yet for any blood work until next month. Last time checked all was good.

I get nauseous if I take the ABX on a empty stomach. If I take it with food or an hour after I don't experience it.

Sometimes my dumb self forgets to do this (maybe a different daily schedule that throw things off). I take it and then later nausea and then I remember "DOH!, why did I take it on an empty stomach!".

When is your husband taking the ABX? On an empty stomach? With food?