Serous Drainage post craniotomy?

Has anyone ever experienced drainage from their incision line after having a craniotomy? My husband is about one month post op and has been having a yellowish drainage for close to one week. He's been seen by his primary care doc who put him on an antibiotic to prevent infection (we don't think he has an infection now) but Robin can't tolerate the medicine (bad nausea). Any wisdom??

I did not experience any of that, in fact my incision started to scab within the first 2 weeks. Personally, I would see/ask the neurosurgeon or neurologist rather than the PCP. I would think a neuro doc would be a little bit more familiar with the healing process. But just from personal experience with any antbiotic, maybe it's causing nausea because it's a strong dosage or strong type of antibiotic. I would assume any infection after brain surgery is something a Dr. would want to take care of ASAP. What kind of stitching, sutures was used? I had dissolvable stitches and was told to watch out for knots in the sutures because sometimes they don't come out on their own (knot is too big to dissolve completely) so the skin will grow around or over it and it will need to be surgically removed (simply cut out)but I don't know if that would cause infection or anything like leakage. I pulled out my own stitching where the knots were to make sure they came out (there was only 2) even though there was probably no need to do that.