No side effects with my first Reclast infusion either. Had it this past Friday Dec. 20th and it's Monday the 23rd now... had 10 cups of water starting the day before and for two days after. Kept it simple and easy by drinking from a two cup glass measuring cup and went about my day making sure to have five of those. Had one extra strength Tylenol (as that's all I had at home) the morning of, one when I got home and 1/2 of one before I went to bed and another two halves in the morning and afternoon of the next day. (As for the 2 cup glass measuring cup as drinking glass: I confess it's a habit to drink water from it anyway as I get caught up in other things and forget to drink and then pay for it in foot cramps at night.. so far only once I forgot to get a nice mug instead and the eye brows went up during a ZOOM call...)