A delicate balance of potassium is needed to properly transmit electrical impulses in the heart. Diuretics often cause low levels of potassium. A low potassium level can disrupt the normal electrical impulses in the heart and lead to irregular heartbeats (arrhythmias). If potassium levels are low, a potassium supplement may be prescribed.

Brands of potassium supplements include:

• Kaochlor.
• K-Lor.
• K-Lyte.
• K-Tab.
• Micro-K.

These products are available in liquid, tablet, powder, and effervescent tablet forms. See Drug Reference for a full list of brand names and other information. (Drug Reference is not available in all systems.)

Blood tests to check for low potassium levels (hypokalemia) are often done during diuretic therapy.

In some cases, an increase in potassium in your normal diet can replace or reduce the need for a supplement. Potassium-rich foods include:

• Dried fruits (raisins, prunes, dates, and figs).
• Fresh fruits (oranges, bananas, cantaloupe, and strawberries).
• Fresh vegetables (potatoes, beets, peas, and tomatoes).
• Salt substitutes (potassium chloride).

People who take potassium supplements and who are also using a salt substitute containing potassium chloride (such as Lite Salt) should ask their doctors about the continued use of the product. Excess potassium intake can cause problems.

Some people have the opposite problem. They have potassium levels that are too high, which can also cause abnormal heart rhythms. Angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers can raise potassium levels in some people. Certain types of diuretics, such as spironolactone, and some beta-blockers also can increase potassium levels. When you take any of these medicines, your doctor will closely watch potassium levels in your blood.