Licorice Poisoning Workup

Updated: Apr 11, 2022
  • Author: Seth Schonwald, MD, FACEP; Chief Editor: Sage W Wiener, MD  more...
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Approach Considerations

Diagnosis is generally confirmed by combination of hypokalemia, increased urinary free cortisol, elevated cortisol-cortisone metabolite ratio, and low or absent urinary aldosterone. A low serum potassium level is the most helpful screening result for establishing mineralocorticoid excess in patients with hypertension. An elevated urinary potassium level may be present. Dilutional anemia may be present, and the hematocrit may be depressed. Hypokalemia, hypernatremia, and water retention are primary problems associated with chronic licorice ingestion. [27]

Licorice poisoning can cause hypokalemic rhabdomyolysis with resultant myoglobinuria and elevated serum creatine kinase level. [28, 29] Myoglobinuria can cause acute tubular necrosis. Emergency physicians should inquire about the consumption of products that may contain natural licorice extract when patients present with unexplained hypertension, hypokalemia, edema, rhabdomyolysis, or myoglobinuria. [30]

If clinically indicated, chest radiography may be performed to assess for pulmonary edema. If urine aldosterone levels are high in a patient with evidence of hypermineralocorticoidism (eg, hypertension, hypokalemia, suppression of the renin-angiotensin system), tumors rather than chronic licorice toxicity are more likely to be the cause, and abdominal computed tomography or magnetic resonance imaging scans may be warranted.

Electrocardiography should be performed to evaluate for hypokalemic changes and QT prolongation or dysrhythmia, including torsades des pointes. Pulse oximetry and arterial blood gas (ABG) measurement can be used to evaluate for pulmonary edema and respiratory muscle weakness.

Many tests are expensive and time-consuming. Consultation with an endocrinologist and toxicologist may be helpful for determining initial workup. Measure serum glycyrrhetinic acid (GRA) and glycyrrhizic acid (GZA) levels with enzyme-linked immunoabsorbent assay (ELISA) and high-performance liquid chromatography (HPLC). Measure the urinary GRA level with gas chromatography–mass spectrometry (GC-MS).

Ascertaining plasma renin activity and urine aldosterone level (24-h collections) is helpful; both are typically low. Determining urine cortisol levels (often elevated) and cortisol-cortisone metabolite ratios (often elevated) may be helpful.