Praise be to Allah.
It is not permissible for you to drink alcohol. The Messenger of Allaah (peace and blessings of Allaah be upon him) has answered this question. In Saheeh Muslim it is narrated that Taariq ibn Suwayd said: I asked the Messenger of Allaah (peace and blessings of Allaah be upon him), “What about the alcohol that we make for medicinal purposes?” He (peace and blessings of Allaah be upon him) said: “No, in fact it is a disease.” He stated that it is a disease and that there is no cure in it. This hadeeth indicates that it is a disease, and in modern medicine, there is general consensus that alcohol is harmful in all cases. Many ( researchers ) have written books and articles on this topic, stating that the tissues of a forty-year old drinker’s body are like those of a sixty-year-old. Even though you may have benefitted as far as your kidneys are concerned, and you have noted that it had an effect, some other part of your body will inevitably have been harmed; alcohol causes harm in all cases. It is not permissible for you to drink it. There are permissible medicines which you can use to treat your kidneys, without using this thing. The Prophet (peace and blessings of Allaah be upon him) said: “O slaves of Allaah, seek medical treatment but do not seek it is anything haraam. For Allaah does not make the cure for this ummah in things that He has forbidden for it.” Even though you may have noticed a benefit in one way, it will inevitably cause a lot of harm in many other ways, as stated in the hadeeth of Taariq ibn Suwayd referred to above, which was narrated by Muslim. And Allaah knows best.