CREAM OF TARTAR has an extremely high potassium content, 495 mg per teaspoon. Our daily requirement for potassium is 3500 mg. This poses a risk for people with kidney disease or those that take medication that decreases the ability of their kidneys to excrete potassium. People who take potassium-sparing diuretics such as aldactone and dyazide, beta-blocker drugs such as propranolol and lopressor, and ACE inhibitor medications such as vasotec and lisinopril, can develop high serum potassium levels, or hyperkalemia, while taking cream of tartar.