Case report Sweet root, bitter pill: liquorice-induced hyperaldosteronism

In December 2002, a 49-year-old man was admitted to our hospital, with headache. He had no significant past medical history other than hypertension, diagnosed at a supermarket, while on holiday in the USA in August 2002. On admission, he was hypertensive, blood pressure (BP) 200/114mmHg with slight ankle oedema and normal systemic examination. Blood tests showedhypokalaemia [2.2mmol/l; normal range (NR) 3.5–5.5] plasma cortisol raised (584 nmol/l; NR 170–540), 24-h urinary cortisol raised (582 nmol;NR 100–379), 24-h urinary catecholamines normal, bicarbonate raised at the upper limit of normal (31mmol/l; NR 19–32) with normal urea, creatinine, full blood count, erthrocyte sedimentation rate (ESR), glucose, liver, bone, thyroid profile, chest X-ray, renal ultrasound and abdominal computerized axial tomogram (CT). Hypokalaemia and uncontrolled hypertension (BP 182/102mmHg) persisted over the next few days. He was treated with potassium supplement and alpha-blockers. Plasma renin-aldosterone studies showed both low recumbent morning renin (0.2p mol/ml/h) and aldosterone (<70pmol/l; NR random 100–800, recumbent 100–450) and persisted at low levels later, on the same day (renin 0.3 pmol/ml/h, aldosterone levels <70 pmol/l). Careful dietary and drug history on the ward round (Day 8) revealed that he had been taking liquorice (3 g/day) for 3 years. Liquorice-induced hyperaldosteronism was diagnosed and he was advised to stop taking liquorice. BP improved to 140/82mmHg, potassium returned to normal 4 days after stopping liquorice and plasma cortisol was normal. One week post discharge, his BP was 165/105mmHg. Five years later, he remains well, home BP in the range of 119–125/76–82mmHg with normal potassium, and continues on aspirin, alpha-blockers and lansoprazole.