You are lucky to have found this group as I hadn't when my EX endocrinologist recommended Reclast. I was clueless that there was actually a recommended prep which both the doctor and infusion center failed to mention. Fortunately a friend was having her Reclast infusion several days before me and was under the care of someone who told her to be well hydrated. Actually the package insert mentions that as well. I drank a bit more than the 16 oz of water and popped 1000 mg of acetaminophen as I left the house. I also took a Claritin the night before which was recommended in another group by a doctor who had had a Reclast infusion herself. I continued drinking water upon my return home and suffered no ill effects. And yes, I found a new endocrinologist.