Background: Liquorice is widely used as a flavour and also as a medical drug. Possible side effects include hypertension, hypokalaemia and metabolic alkalosis.
Materials and methods: We present a case history and a review on liquorice intoxication based on relevant literature found from searches on Medline.
Results and interpretation: A 19-year-old girl was admitted to hospital with severe hypertension, hypokalaemia and metabolic alkalosis. Urine analysis showed inhibition of 11-beta-hydroxysteroid dehydrogenase. It turned out that she ingested a lot of liquorice; after she stopped eating it she became normotensive without any medication. Three months later there were no signs of inhibition of the enzyme. The active component of liquorice is glycyrrhetinic acid, which inhibits the enzyme 11-beta-hydroxysteroid dehydrogenase. This enzyme promotes the conversion of cortisol to cortisone and is thereby responsible for the specificity of the mineralocorticoid receptor to aldosterone in the collecting tubules. Inhibition of the enzyme allows cortisol to act as the major endogenous mineralocorticoid producing a marked elevation in mineralocorticoid activity, resulting in hypertension, hypokalaemia and metabolic alkalosis.