I never been on Effexor but my roommate was .It a very hard med. to come off of one of the hardest. If I was you I would go to a doctor who when you ask if effexor is bad for your kidneys will tell you!!!! There are alot of meds out there that are very bad for your kindeys and liver you need to have blood test few times a year to make sure their Lv. are not to high for they can shut down your liver or kidneys .Not to scare you but you need to check into this right away.Sorry i cant help more but you really need to talk to a doctor.