Clinical Risk Factors of Licorice-Induced Pseudoaldosteronism Based on Glycyrrhizin-Metabolite Concentrations: A Narrative Review.

Licorice, the dried root or stolon of Glycyrrhiza glabra or G. ularensis, is commonly used worldwide as a food sweetener or crude drug. Its major ingredient is glycyrrhizin. Hypokalemia or pseudoaldosteronism (PsA) is one of the most frequent side effects of licorice intake. Glycyrrhizin metabolites inhibit type 2 11ß-hydroxysteroid dehydrogenase (11ßHSD2), which decomposes cortisol into inactive cortisone in the distal nephron, thereby inducing mineralocorticoid receptor activity. Among the several reported glycyrrhizin-metabolites, 18ß-glycyrrhetyl-3-O-sulfate is the major compound found in humans after licorice consumption, followed by glycyrrhetinic acid. These metabolites are highly bound to albumin in blood circulation and are predominantly excreted into bile via multidrug resistance-associated protein 2 (Mrp2). High dosage and long-term use of licorice are constitutional risk factors for PsA. Orally administered glycyrrhizin is effectively hydrolyzed to glycyrrhetinic acid by the intestinal bacteria in constipated patients, which enhances the bioavailability of glycyrrhizin metabolites. Under hypoalbuminemic conditions, the unbound metabolite fractions can reach 11ßHSD2 at the distal nephron. Hyper direct-bilirubin could be a surrogate marker of Mrp2 dysfunction, which results in metabolite accumulation. Older age is associated with reduced 11ßHSD2 function, and several concomitant medications, such as diuretics, have been reported to affect the phenotype. This review summarizes several factors related to licorice-induced PsA, including daily dosage, long-term use, constipation, hypoalbuminemia, hyper direct-bilirubin, older age, and concomitant medications.

Liquorice-induced hypokalaemia in patients treated with Yokukansan preparations: identification of the risk factors in a retrospective cohort study.

OBJECTIVE: To evaluate serum potassium levels and rates of hypokalaemia in patients treated with liquorice-containing Japanese traditional Kampo-medicines Yokukansan (YK) and Yokukansan-ka-chinpihange (YKCH). DESIGN: Retrospective cohort study. SETTING: Patients receiving YK preparations for dementia and other psychiatric disorders in the University of Tsukuba Hospital in Japan. PARTICIPANTS: 389 patients (male/female: 174/215, 68.6±16.1 years) were treated with YK preparations for 231 days (range 6-2788 days). Patients whose potassium levels were <3.6 mEq/L before administration of YK preparations, and drug non-compliant patients, were excluded. MAIN OUTCOME MEASURE: The occurrence rate of hypokalaemia and assessment of the risk factors for YK preparation-induced hypokalaemia. RESULTS: Of the 389 patients treated with YK preparations, 94 (24.2%) developed hypokalaemia (potassium levels <3.6 mEq/L) 34 days (range 1-1600 days) after administration of the preparations. 36 (38.3%) patients had co-administration with lower potassium-inducing drugs (LPIDs; diuretics, glucocorticoids, mineralocorticoids and glycyrrhizin), which was more frequent in the patients without hypokalaemia (17.3%) (p<0.05). A Cox proportional hazard model identified four risk factors for hypokalaemia: YK administration (not YKCH) (HR 3.093, 95% CI 1.408 to 6.798), co-administration of LPIDs (HR 2.743, 95% CI 1.754 to 4.289), hypoalbuminaemia at baseline (HR 2.145, 95% 1.360 to 3.384), and full dosage administration (7.5 g/day) (HR 1.600, 95% CI 1.005 to 2.549). CONCLUSIONS: Serum potassium monitoring should be done at least monthly in patients with the following risk factors: LPID co-administration, YK administration, hypoalbuminaemia, and full dosage administration.