Liquorice-induced pseudohyperaldosteronism: a rare cause for severe hypertension

This case report describes an adult man in his 50s with a history of type 2 diabetes and previously well-controlled hypertension, who presented with uncontrolled hypertension, muscle weakness and fatigue. Biochemical testing revealed hypokalaemia. There was no evidence of renal/renovascular disease. Evaluation for primary hyperaldosteronism revealed suppressed renin concentration with low aldosterone levels. Detailed history taking revealed the daily consumption of three to four cups of liquorice root tea for 3 months. Glycyrrhetinic acid, a metabolite of glycyrrhizic acid found in liquorice, inhibits the 11 beta-hydroxysteroid dehydrogenase-2 (11β-HSD2 enzyme present at the renal tubule, leading to cortisol-mediated mineralocorticoid receptor activation. The diagnosis of liquorice-induced pseudohyperaldosteronism was made, and the discontinuation of liquorice with short-term use of mineralocorticoid receptor blockers led to normalisation of blood pressure and serum potassium. This case highlights the importance of considering the possibility of excess use of liquorice in the differential diagnosis of unexplained hypertension, especially in the context of low-renin hypertension.