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Potassium chloride: 7 things you should know

Medically reviewed by Carmen Pope, BPharm. Last updated on April 5, 2023.

1. How it works

  • Potassium chloride tablets replace potassium in your body.
  • Potassium is a mineral that is the major cation of intracellular fluid and is also found naturally in many foods. It is essential for the conduction of nerve impulses in the heart, brain, and skeletal muscle, for the contraction of cardiac, skeletal, and smooth muscles, for the maintenance of normal renal function, for acid-base balance, for carbohydrate metabolism, and for gastric secretion. Potassium levels can become low if you have an adrenal gland disorder, a prolonged bout of diarrhea or vomiting, chronic laxative abuse, taking diuretics (water pills), if your magnesium levels are low, or with certain other medications or medical conditions. Symptoms of low potassium include muscles that feel weak, cramp, or twitch; and abnormal heart rhythms. Potassium supplements replace missing potassium.
  • Potassium is classed as a mineral supplement.

2. Upsides

  • Potassium chloride supplements are used to prevent and treat low blood levels of potassium (this is also called hypokalemia).
  • Available as extended-release capsules and tablets, sprinkles, an oral solution, and in a sterile solution for intravenous administration.
  • Extended-release supplements release potassium chloride slowly over time.
  • The dosage of potassium supplements is expressed as a mEq (milliequivalent). This is a unit of measurement that is applied to electrolytes and indicates the chemical activity or combining power of the electrolyte. For example, potassium chloride 10 mEq is a microencapsulated form of potassium chloride that contains 750 mg of potassium chloride USP equivalent to 10 mEq of potassium.
  • Normal daily requirements of potassium for adults are 40 to 80 mEq/day. For the prevention of hypokalemia, 20 to 40 mEq/day should be given in one or two divided doses. To treat hypokalemia, dosages of up to 100 mEq/day may be needed; consider the IV route if deficits are severe and ongoing losses are great. Lower dosages are used in children; consult the product information.
  • Generic potassium chloride supplements are available.

3. Downsides

If you are between the ages of 18 and 60, take no other medication or have no other medical conditions, side effects you are more likely to experience include:

  • Diarrhea, stomach pain, muscle weakness, numbness or tingling in the hands, feet, or mouth, uneven heartbeat. Side effects are more likely if high dosages of potassium chloride are taken.
  • May not be suitable for some people including those with kidney failure, Addison's disease, severe burns, or severe wounds.
  • Should also not be taken by a person who is dehydrated or has high levels of potassium in their blood.
  • Certain medical conditions such as dysphagia, swallowing disorders, or severe gastrointestinal motility disorders may cause potassium chloride tablets to maintain contact with the gastrointestinal mucosa for long periods. Consider the use of liquid potassium in these patients. Potassium chloride tablets should not be taken on an empty stomach.
  • Available as tablets, a powder, for IV administration, and in granulated and liquid form. The IV form should only be used intermittently and only for more severe depletion situations in people undergoing ECG monitoring.
  • May interact with several other medicines including digoxin, quinidine, ACE inhibitors, and several diuretics.

Note: In general, seniors or children, people with certain medical conditions (such as liver or kidney problems, heart disease, diabetes, seizures) or people who take other medications are more at risk of developing a wider range of side effects. View complete list of side effects

4. Bottom Line

Potassium chloride is a mineral used to replenish potassium within our body. It may irritate the stomach; however, other side effects generally only occur with higher dosages.

5. Tips

  • Take potassium chloride tablets with food or just after a meal to reduce the risk of stomach irritation. Follow with a full glass of water.
  • Some foods (such as squash, spinach, cabbage, lentils, kidney beans, orange juice, bananas, tomatoes, zucchini, or cucumber) are also high in potassium. Ask your doctor if there is a limit to how much of these foods you can eat. Some salt substitutes or low-salt dietary products also contain potassium - be careful how much of these you eat.
  • Do not crush, break, chew, or suck extended-release potassium chloride tablets as doing this may cause too much potassium chloride to be released at once, irritating your throat and stomach. Tablets are designed to release potassium slowly over time. Sometimes you may notice the remnants of a potassium chloride tablet in your stool.
  • Can be taken with some diuretics (water pills) but not others. Talk to your doctor or pharmacist about drug interactions if you take other medications.
  • Mix the powder, granule, or liquid form with water or fruit juice and drink the mixture slowly over 5 to 10 minutes.
  • If you have had bariatric surgery, talk to your doctor about how to take potassium supplements if prescribed. Potassium is a known GI irritant.
  • Your doctor may require you to come in for regular blood tests to make sure your potassium chloride tablets are adequately replacing your blood levels of potassium. Sometimes your heart rate may need to be checked as well. Make sure you keep to your scheduled appointments.
  • Contact your doctor straight away if you experience confusion, anxiety, extreme thirst or increased urination, numbness, black or bloody stools, cough up blood, or vomit up black flecks.
  • Do not stop taking potassium chloride without your doctor's advice as it may worsen your condition.
  • Take only as directed. If you miss a dose, take it as soon as you remember, but if you don't remember until the next day, do not take a double dose.

6. Response and effectiveness

  • Tablets start disintegrating within a few minutes; however, potassium chloride tablets are released slowly over several hours which reduces the risk of stomach irritation.
  • Potassium chloride is usually taken once daily until potassium levels are within the normal range.

7. Interactions

Medicines that interact with potassium chloride may either decrease its effect, affect how long it works, increase side effects, or have less of an effect when taken with potassium chloride. An interaction between two medications does not always mean that you must stop taking one of the medications; however, sometimes it does. Speak to your doctor about how drug interactions should be managed.

Common medications that may interact with potassium chloride include:

  • aliskiren
  • angiotensin II receptor blockers, such as captopril or enalapril
  • anticholinergics such as benztropine
  • drospirenone
  • intraconazole or ketoconazole
  • glycopyrrolate
  • heparin
  • nicorandil
  • potassium-sparing diuretics, such as spironolactone.

Note that this list is not all-inclusive and includes only common medications that may interact with potassium chloride. You should refer to the prescribing information for potassium chloride for a complete list of interactions.


Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use potassium chloride only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Copyright 1996-2023 Revision date: April 5, 2023.