Spironolactone (Aldactone) is a type of medication known ... However, they might recommend starting with 25 mg a day and slowly increasing your dose to reduce your risk of side effects.

The landmark Randomized Aldactone Evaluation Study (RALES), published in 1999, showed that spironolactone, a potassium-sparing diuretic, improves outcomes in patients with severe heart failure.

25–50 mg daily for 1 year. Five patients taking spironolactone and one patient on placebo developed hyperkalemia within 2–12 weeks of initiation of study medication and were excluded.