Dave, since you had such a big drop in your GFR over a relatively short period of time, I would highly suggest that you get an evaluation from either your primary doctor or an immunologist.

Have you had food poisoning? Are you on other drugs? OTCs?

Do you have high blood pressure? Did they do an ultrasound of your kidneys to look for renal artery stenosis?

A drug is an easy answer as to why this has occurred, but that might not be the correct answer. You really need to know why!

I hope you'll ask for more investigating right away.

Annie