Licorice root tea, hypokalaemia, and resistant hypertension in a herder's wife

Likeliest cause: licorice root (Glycyrrhiza species, including Glycyrrhiza uralensis, which grows in Mongolia) causing pseudohyperaldosteronism - apparent mineralocorticoid excess.

Mechanism, step by step

• The root contains glycyrrhizin, which is hydrolysed in the gut to glycyrrhetinic acid.
• Glycyrrhetinic acid inhibits 11β-hydroxysteroid dehydrogenase type 2 in the distal renal tubule. Normally this enzyme converts cortisol to the inactive cortisone, protecting the mineralocorticoid receptor from the much higher cortisol concentration.
• With the enzyme blocked, cortisol occupies and activates the mineralocorticoid receptor, producing sodium retention, potassium and hydrogen loss, hypertension, and metabolic alkalosis - the picture of hyperaldosteronism, but with low aldosterone.
• Her hydrochlorothiazide adds a second potassium-losing mechanism, which is why she became symptomatic; ibuprofen adds sodium retention and reduces renal potassium excretion control.

Confirmatory tests

• Plasma renin activity and aldosterone: both suppressed. In primary hyperaldosteronism aldosterone is high with suppressed renin; here both are low, which is the discriminator.
• A raised urinary cortisol-to-cortisone ratio (or serum glycyrrhetinic acid) supports licorice exposure.
• Resolution of hypertension and hypokalaemia within days to a couple of weeks after stopping the root is the practical confirmation.
• Check magnesium and thyroid function, since hypomagnesaemia and thyrotoxicosis also cause hypokalaemia; the metabolic alkalosis and suppressed renin point away from diuretic effect alone.

The conversation first: do not frame this as 'your traditional remedy is poison'. Say: 'This root works on the same hormone system as your blood pressure medicine. Together they have dropped your potassium to 2.8, which is why your muscles are weak and your heart rhythm is abnormal. If you keep taking it, the risk is a dangerous heart rhythm.' Acknowledge that it genuinely helps her stomach, and offer a plan for the stomach symptom that she can accept - review for gastritis or Helicobacter infection, and offer a suitable alternative if indicated. Ask her to bring or describe the root; if identification is possible, involve a pharmacist or doctor trained in traditional medicine so that a registered traditional preparation, with a known dose, can replace an unmeasured root.

Clinical management

• Stop the licorice - tea, chewed root, and any sweets or confectionery containing licorice extract.
• Potassium: oral potassium chloride with meals; at 2.8 mmol/L with ECG changes she needs replacement and a repeat potassium and magnesium within 24–48 hours, with ECG monitoring.
• Antihypertensive: hydrochlorothiazide is the wrong drug for her now - it worsens potassium loss. Stop it and start a regime less likely to waste potassium, such as amlodipine or an ARB, with review in one to two weeks; a potassium-sparing diuretic such as spironolactone or amiloride is effective in licorice excess but should be started cautiously under supervision because potassium can overshoot.
• Ibuprofen: advise against regular use - it raises blood pressure and reduces renal potassium excretion. Offer paracetamol and physiotherapy for the back.
• Recheck potassium, bicarbonate, and blood pressure at 1 week and 4 weeks; recovery is usually complete but relapse is common if she returns to the tea.

Quality issues

• No identity, no dose: an unlabelled root means the species, plant part, and glycyrrhizin content are unknown. Wild harvesting can confuse Glycyrrhiza with other roots, and potency varies several-fold between batches - which is why the same tea can be harmless for one person and toxic for another.
• Contamination: unregulated harvested or imported material may carry heavy metals, pesticide residues, or microbial contamination; this is a particular concern when the product is imported informally across borders.
• Interaction with medicines is a quality-of-use issue: the patient did not consider a 'natural' tea to be a medicine, so she never mentioned it and the prescriber never asked.

Regulatory issues

• Herbal and traditional medicines in Mongolia fall under the national medicines framework, which requires authorisation and Mongolian-language labelling for products placed on the market. A root brought by a relative is outside that framework: it has no authorisation, no label, no batch, and no responsible manufacturer, so it cannot be assessed or recalled.
• The case argues for two practical measures: a standard question about herbal and traditional products at every dispensing point, and public information that natural does not mean interaction-free, especially with warfarin, diuretics, and antihypertensives.

Documentation and reporting

• Record the suspected herbal product, the duration and amount, the clinical findings, and the outcome in the medical record and in the pharmacy file.
• Report it to the National Agency for Medicines and Medical Devices as a suspected adverse reaction to a herbal product, so that a signal can be built even though no batch exists to test.
• Give her written advice listing licorice (and 'root tea of unknown identity') to avoid, and tell her to show it at every future visit.