K-Dur Potassium Salts tablets, extended-release tablets or capsules What do potassium tablets, extended-release tablets or capsules do?POTASSIUM (K-Norm(R), K-Dur(R), Slow-K(R), Micro-K(R)) is a naturally occurring salt that is important for the normal functioning of the heart, muscles, and nerves. Too much or too little potassium in the body can cause serious problems. Potassium occurs naturally in many foods and is normally supplied by a balanced diet. Potassium supplements are used to treat potassium deficiency (hypokalemia) that occurs in certain illnesses or from use of certain medicines. Potassium comes as different salts and generic potassium salts are available in tablet form.