From the FDA Drug Label
The diagnosis of potassium depletion is ordinarily made by demonstrating hypokalemia in a patient with a clinical history suggesting some cause for potassium depletion In interpreting the serum potassium level, the physician should bear in mind that acute alkalosis per se can produce hypokalemia in the absence of a deficit in total body potassium while acute acidosis per se can increase the serum potassium concentration into the normal range even in the presence of a reduced total body potassium
The reasons for abnormally low potassium (hypokalemia) include:
- Potassium depletion: demonstrated by hypokalemia in a patient with a clinical history suggesting some cause for potassium depletion 1
- Acute alkalosis: can produce hypokalemia in the absence of a deficit in total body potassium 1 Note that the FDA label does not provide an exhaustive list of reasons for hypokalemia, and other causes may exist.
From the Research
Chronic low potassium (hypokalemia) is most commonly caused by excessive potassium loss through urine due to certain medications, kidney disorders, or hormonal conditions, and addressing the underlying cause is crucial for effective management, as stated in the most recent study 2. The most common reasons for chronic hypokalemia include:
- Excessive potassium loss through urine due to certain medications like diuretics (especially thiazides and loop diuretics)
- Kidney disorders
- Hormonal conditions like hyperaldosteronism
- Gastrointestinal losses from chronic diarrhea, vomiting, or laxative abuse Some medications besides diuretics that can lower potassium include certain antibiotics, high-dose steroids, and some asthma medications like albuterol, as noted in 3 and 4. Dietary factors rarely cause chronic hypokalemia alone but inadequate intake can worsen other causes, and certain genetic disorders affecting kidney function, such as Bartter syndrome or Gitelman syndrome, can lead to persistent potassium loss, as discussed in 5. Treatment depends on identifying and addressing the underlying cause while supplementing potassium through oral supplements like potassium chloride or potassium-rich foods, and if you have chronic hypokalemia, it's essential to work with your healthcare provider to determine the specific cause through blood tests, urine studies, and possibly hormone testing, as untreated low potassium can lead to muscle weakness, heart rhythm problems, and other serious complications, as emphasized in 2 and 4. Key considerations for managing hypokalemia include:
- Determining the need for urgent treatment through a combination of history, physical examination, laboratory, and electrocardiography findings, as outlined in 3
- Using oral or intravenous potassium for treatment, and considering potential causes of transcellular shifts, as noted in 3 and 4
- Preventing cardiac conduction disturbances, and managing hyperkalemia when chronic and in the emergency or hospital ward, as discussed in 5.