Short answer: The Aldactone (spironolactone) label advises against it unless a prescriber says otherwise. Spironolactone can raise blood potassium (hyperkalemia), and the label says potassium supplements, potassium salt substitutes and other drugs that raise potassium may lead to severe hyperkalemia. It says patients should avoid potassium supplements and high-potassium foods including salt substitutes, and that potassium is checked within 1 week of starting.
Aldactone has hyperkalemia in its Warnings and Precautions. The risk goes up with reduced kidney function and with potassium supplements, potassium-containing salt substitutes, or drugs that raise potassium such as ACE inhibitors and angiotensin receptor blockers (ARBs).
Its drug interaction section says combining Aldactone with potassium supplements, potassium salt substitutes, a diet rich in potassium, or drugs that raise potassium, including ACE inhibitors, ARBs, NSAIDs and heparin, may lead to severe hyperkalemia. For heart failure patients who start Aldactone, it says potassium supplements should generally be stopped. Its patient counseling section says to advise patients to avoid potassium supplements and foods high in potassium, including salt substitutes.
The label asks for blood potassium to be checked within 1 week of starting or changing the Aldactone dose, and regularly after that, with more frequent checks for people on other drugs that raise potassium or with reduced kidney function. If potassium runs high, it says to lower the dose or stop Aldactone and treat the high potassium.
For heart failure, the label starts at 25 mg once a day when potassium is 5.0 mEq/L or lower and kidney function (eGFR) is above 50, and suggests 25 mg every other day when eGFR is 30 to 50 because of the hyperkalemia risk. The label also says Aldactone can lower sodium, magnesium and calcium, so it asks for periodic electrolyte checks.
The NIH Office of Dietary Supplements potassium fact sheet says potassium-sparing diuretics such as amiloride and spironolactone reduce how much potassium leaves in urine and can cause hyperkalemia, and that experts recommend monitoring potassium, especially with kidney problems. It says ACE inhibitors and ARBs do the same, while loop and thiazide diuretics do the opposite and can lower potassium.
ODS says high potassium can have no symptoms, but severe cases can cause muscle weakness, paralysis, palpitations, a burning or prickling feeling in the hands and feet, and heart rhythm problems that can be life threatening. It also says very high amounts of potassium supplements or potassium salt substitutes can cause sudden hyperkalemia even in healthy people.
Salt substitutes are often potassium chloride. Electrolyte drinks, some multivitamins and some sports powders also contain potassium. None of these are named in the label, but they add to the potassium the label is concerned with.
If you use any of these, your prescriber can say whether they fit with your dose and how often potassium should be checked. Dose Track keeps spironolactone, supplements and your potassium results in one place.
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