Can antibiotics cause water retention/weight gain?

I have been on rifaximin antibiotic twice previously (for SIBO) and both times I have gained about 6-8 pounds over the ten day antibiotic course. I lost this rapidly after stopping the medication.
I assume this is water retention since I gained/lost it so quickly and did not change my eating or exercise habits??
I'm getting ready for another round with the meds (and I may be on them for longer this time), so just wanted to know if this is normal.

[SassyLassie]

Drugs have different reactions on different folks, so, this could just be a normal reaction for you. I would call your pharmacist and ask him/her and see what they have to say.

[faze_action]

Yes, I probably should talk with the pharmacist. I just have never heard of antibiotics causing water retention before, but that seems to be what happens to me when I have taken them. I do not generally gain weight easily, so the fact that I put on so much weight in such a short time (and then lost it so quickly afterwards) was a red flag for me.

[faze_action]

Just as an addendum to my original post:

I did talk with the pharmacist and she told me that, for this particular antibiotic anyway, "weight changes" are an uncommon side effect. I assumed "weight changes" to mean either water retention, weight gain, or both.