Question: What effects does spironolactone have on my blood potassium and should I be monitored while on it?
Answer: Because spironolactone is commonly used in heart failure treatment, its effects on your kidneys are really important. It turns out that spironolactone causes the kidney to retain or hang on to potassium. And it can increase the blood potassium level, and in some patients actually quite significantly, and even in a few to dangerous levels. So with a new addition of spironolactone to your medical regimen, the blood potassium level should be monitored. Initially the first few days after starting it, and then every couple of weeks for probably a month or two to make sure that your blood potassium levels are okay and are not too elevated. Spironolactone can also sometimes be used to replace potassium supplements, so if you're taking potassium supplements with your loop diuretic -- Lasix or what -- and spironolactone is added, then the potassium level should be checked because the spironolactone may well reduce the need for potassium supplementation.