Kidney damage. And still is nauseous.

My mother had UTI problem and was admitted to hospital for a week and her serum creatinine was 1.5. She was again admitted in the hospital because she was again getting chills and fevers and doctor told me that her kidney is nearly damaged and creatinine level was increased by 3.2, after that she was given an antibiotic injection ( Epime-TZ ) through NS which resulted in increased creatinine by 4.2. After that doctor changed the antibiotic injection and started giving Lupinem. Firstly we observed that creatinine level was decreasing till it was 2.7 then next day it was 3.1 which was unexpected. Her K level was increased by 5.7. Doctor carelessly said that there is not a problem and gave us a weekly follow up . I want a second opinion as she is not showing any positive signs of recovery yet and has been and still is nauseous.