Suggest Treatment For Pain In Both Sides Of Kidney Area And Swollen Legs

My father is 72 years, affected with kidney infection problem for many years, but recently he is suffering from both side kidney pain and leg swelling. As per pathology report his potassium has increased at the level of 5.9 and started on medicine as K-Bind powder, now he is feeling some pain in right side what do I further for his treatment