Because you tolerated the iv drug, I wonder if the issue is not the antibiotic itself, but the capsule and/or the fillers used? My sister-in-law does not tolerate any drugs (or foods) with red dye added. I can handle the original brand name version of some meds, but not the generic subs. My Mom and a friend of mine only were able to use brand name Synthroid, no generics...

This would be a puzzle for an allergist specializing in meds - maybe within Mayo or another big multidisciplinary practice?