How much nsaids is too much? I take ibuprofen.

So sorry to hear that you are having this problem. I have a friend at work that said that his kidney problems are caused by an autoimmune issue.

As far as to why they will increase the mestinon dosage, it is most likely because the kidneys are what gets rid of your old mestinon. If you take as much as you used to, your blood levels may get to toxic levels.

"Renal Dysfunction
In anephric patients (n=4), the elimination half-life increased 3 fold and the systemic clearance
decreased by 75%. Therefore caution should be observed when administering pyridostigmine
bromide to patients with impaired renal function."

Source: http://www.fda.gov/downloads/Drugs/E.../UCM133154.pdf

(This was from the military use of the drug, but the mechanism is the same.)