Can Benadryl be bad for your Kidneys?

Depending on the amount of Benadryl you may taking can and does have a certain effect on the Nephrons in your kidneys, and to a lesser degree the liver. Be very careful how much you take and how often you use it. It is not common however, but if you're at all concerned be seek out the advice of your PMC doctor. Just to be on the safe side. No medications are safe when taken in amounts they are not intended for, and if you find they are not working in the manner you expect, then it is time to see your Doctor, Please be careful, Bless You, and good luck, and please to check back often, other posters here may have better or more informed answers than I do.