From the Guidelines
Metabolic alkalosis is primarily caused by excessive loss of hydrogen ions or gain of bicarbonate in the body, with the main causes including vomiting, diuretic use, excessive alkali administration, severe potassium depletion, and certain endocrine disorders. The causes of metabolic alkalosis can be categorized into several main groups, including:
- Excessive loss of hydrogen ions, such as through vomiting or nasogastric suction, which removes acidic gastric contents 1
- Gain of bicarbonate, such as through excessive alkali administration, like sodium bicarbonate or antacids containing calcium carbonate
- Certain endocrine disorders, like hyperaldosteronism or Cushing's syndrome, which can lead to increased renal bicarbonate reabsorption
- Diuretic use, particularly loop and thiazide diuretics, like furosemide and hydrochlorothiazide, which increase renal bicarbonate reabsorption 1
- Rare genetic disorders, such as Bartter and Gitelman syndromes, which mimic the effects of diuretics and can cause hypokalemic metabolic alkalosis 1 Other causes of metabolic alkalosis include:
- Contraction alkalosis, which can occur with volume depletion, as the kidneys retain sodium and bicarbonate
- Milk-alkali syndrome, which results from excessive calcium and absorbable alkali intake
- Severe potassium depletion, which can impair renal bicarbonate excretion
- Certain tubulopathies, such as congenital chloride diarrhea, which can cause pronounced hypokalemic and hypochloremic metabolic alkalosis 1 It is essential to identify and address the underlying cause of metabolic alkalosis, as treatment typically involves correcting fluid and electrolyte imbalances, and in severe cases, administering chloride-containing solutions to help the kidneys excrete excess bicarbonate.
From the FDA Drug Label
Supplemental potassium chloride and, if required, an aldosterone antagonist are helpful in preventing hypokalemia and metabolic alkalosis The causes of metabolic alkalosis are not explicitly stated in the label, but it can be prevented by avoiding hypokalemia.
- Hypokalemia may contribute to the development of metabolic alkalosis. 2
From the Research
Causes of Metabolic Alkalosis
The causes of metabolic alkalosis can be divided into several categories, including:
- Generation of alkalosis due to excessive hydrogen ion loss by the gastrointestinal tract (e.g. vomiting) or by the kidney (e.g. use of loop diuretics) 3, 4, 5, 6
- Exogenous base gain, such as oral or parenteral alkali intake 4, 5
- Maintenance of alkalosis due to factors such as hypovolemia, chloride depletion, hypokalemia, hyperaldosteronism, renal failure, or a combination of these factors 3, 4, 5
Clinical States Associated with Metabolic Alkalosis
Several clinical states are associated with metabolic alkalosis, including:
- Vomiting 3, 4, 5, 7
- Aldosterone or cortisol excess 4, 5
- Licorice ingestion 4, 5
- Chloruretic diuretics 4, 7
- Excess calcium alkali ingestion 4
- Genetic diseases such as Bartter syndrome, Gitelman syndrome, and cystic fibrosis 4, 5
Factors that Interfere with Bicarbonate Excretion
Factors that interfere with the kidney's ability to eliminate excess bicarbonate include: