Could someone please kindly explain what the difference is between Klor-Con and Klor-Con M? Per FDA, the two products are not interchangable. I looked into the package inserts for both products and still could not figure out the differences. They are both extended release potassium chloride. The Klor-Con M contains microencapsulated crystals and it's an immediately dispersing tablet. Also, is Klor-Con 20Meq discontinued? THANKS!