Background
Glycyrrhizin glabra, licorice root, is an ingredient in traditional herbal remedies and confectionery products. Its main active ingredient, glycyrrhizin, has anti-inflammatory and antioxidant effects,(1) but also has a potentially hazardous association with pseudohyperaldosteronism.(1)
Case
A 17-year-old girl presented to the emergency department with chest pain, nausea and tremors. She had been suffering from intermittent nausea and abdominal pain for two years but had no other medical conditions, no regular prescription medication, and denied any substance abuse. Physical examination was unremarkable except for a tachycardia of 110 beats per minute with a blood pressure of 102/62mmHg. Blood tests revealed hypokalaemia 2.8mmol/L (3.6-5.2mmol/L), elevated lactate 8.7mmol/L (0.5-2.2mmol/L), and leukocytosis 17.9 x 109/L (4.0-12.0 x 109/L). Serum aldosterone and renin were 151pmol/L and 28pmol/L respectively, with an aldosterone-renin ratio of 5.4.
Further history revealed she had taken “GIT Regenex”, a herbal remedy containing Glycyrrhizin glabra, for ten days prior. Dosing instructions for this remedy recommended a daily glycyrrhizin intake of 157.34mg, exceeding the daily maximum of 100mg recommended by the World Health Organisation. She responded well to oral potassium and intravenous magnesium replacement overnight and was discharged home. A safety report was sent to the Therapeutic Goods Administration for GIT Regenex.
Discussion
Intestinal bacteria convert glycyrrhizin to 3-monoglucoronyl-18-glycyrrhetinic acid and glycyrrhetinic acid (GA).(2) GA inhibits the 11β – hydroxysteroid dehydrogenase 2 enzyme in the distal nephron, decreasing conversion of cortisol to cortisone, and increasing mineralocorticoid receptor activation through cortisol binding.(2) This causes kaliuresis and fluid retention similar to primary aldosteronism, but with normal or low serum aldosterone and renin.(3) At least 16 individual cases and 18 clinical trials have described weakness, hypertension, and even ventricular arrhythmias associated with licorice since 1970.(3-18)
Conclusion
Our case highlights the need to consider licorice-induced pseudohyperaldosteronism caused by complementary therapies in the differential diagnosis of hypokalaemia.