Salt substitute is a tricky replacement

Dear Dr. Roach: I am a 91-year-old man with swollen legs. I take 20 mg of furosemide and 20 mEq of Klor-Con daily. I understand that the Klor-Con is to replace the potassium loss caused by the former. I also understand that I should reduce my salt intake. The loss of table salt is extremely difficult. I have started using a salt substitute called NoSalt, containing potassium. Since the salt substitute is providing me with potassium, can I eliminate or lower my intake of Klor-Con? — E.P.

Sodium and potassium are critically important minerals that need to be regulated. The kidney is normally very good at it, but the furosemide you are taking forces the kidney to lose both sodium and potassium along with water. Prolonged use of furosemide can lead to abnormalities.

Low potassium can cause muscle cramps and weakness. However, high potassium is even more dangerous, as it can lead to a fatal heart rhythm. Potassium replacement needs to be properly managed.

Salt substitutes are essentially the same as the Klor-Con you are taking. The first ingredient in your salt substitute is potassium chloride. According to the nutrition label, 1⁄4 teaspoon of the salt substitute contains 650 mg of potassium. Twenty milliequivalents of Klor-Con contains 800 mg of potassium.

With the prescription KlorCon, you are getting precisely the same amount every day. Unless you are meticulously careful, your intake of the salt substitute is likely to vary a bit one day to the next. For a person with healthy kidneys, it’s probably fine. Your kidneys can probably get rid of any excess potassium.

I should note that treatment with diuretics like furosemide (Lasix) is not an effective longterm treatment for most people with swollen legs. The swelling is commonly due to vein problems in the legs.