I had trouble with kidney malfunction on lithium no matter how much water I drank (but it sure helped stabilize me & convinced me that I was bp & that there was help out there). There are plenty of other meds to try if lithium is not for you. They even ordered a sonogram to see if I had a tumor on my kidney that was causing the problems--I'm like, yikes, I came in here crazy not sick! No tumor. Just couldn't handle the lithium.--Suzy