I think we all sorta worry about taking a new medication and how it may react with other meds. I have taken Antivert off and on for years with no problem. ( Sorry you did have a concussion , I mentioned that in your original post about going to ER to get checked out ! )

Is there a chance that the pharmacist was being "silly" about the water issue, since you have a long list of allergies? I know my Mom has a 3x5 card full on both sides of her allergies (meds and foods - listing foods is always a very good idea as many times certain meds should not be taken with certain food allergies), and the pharmacist always makes a joke when Mom walks into pharmacy to get a new med....like " ut oh, gotta get out all the books I have to make sure we can fill this one for ya"..............Just a thought there. I hope you are feeling better, and that the Antivert helped !