The nephrologist added extra lasix despite the creatinine level increase, can aldactone be less harmful than lasix? Any way to figure out water retention levels to prevent overuse of lasix at homr? Patient already maintaining 500ml fluid restriction

Over diuresis. Aldactone (spironolactone) may increase potassium level in blood .body wt is good way to monitor the extent of diuresis.
Renal failure. Aldactone (spironolactone) may increase the serum potassium level, in renal insufficiency high potassium may be a problem to start with, I am sure your nephrologist know your kidney function well. Clinically water retention is gauged with swelling and body weight.
Trust your doc. Aldactone (spironolactone) may be bad for someone with kidney failure. Trust your nephrologist. If you have questions, raise them with him/her .
Nephrologist. You will have to trust the judgment of the nephrologist as the patient already has abnormal creatinine levels and has only symptomatic low blood pressure to use as a guide to too much Lasix (furosemide).