I don’t think antibiotics break the fast. I would just take a week off or take the medication as prescribed and eat like I usually do depending on how well my stomach was tolerating the meds.
Some antibiotics this would not matter for me, others really upset my stomach and I would just eat and get back on track in a week.
Not sure how far you are into IF but for me this is a full lifestyle change. I eat on my IF schedule every day and have for years. But I also abandon it on vacation or if I’m ill. Since it is just s as part of my life it has never been a problem to just slide right back into the routine.
For me it works because I’m both militant about it but also very much not militant about it. I hardly ever skip but if I think to myself “you should eat breakfast today” I almost always listen to that voice because it means something is going on!
Anyway early If me would have stressed about this question but from a long time faster don’t stress about a week. It’s a marathon not a sprint!