Jie Geng Tang桔梗汤

The Gan Cao dominates the safety picture because the classical proportion gives it twice the weight of Jie Geng. Sustained or high-dose Gan Cao causes pseudoaldosteronism: sodium and water retention, low potassium, rising blood pressure, oedema and, at the extreme, muscle weakness or arrhythmia from hypokalaemia. It is therefore unsuitable at that proportion in hypertension, heart failure, kidney disease or existing low potassium, and needs care alongside diuretics, corticosteroids and digoxin. Jie Geng in larger doses irritates the stomach and can itself cause nausea; it lifts, so it is avoided where there is upward-rebelling qi with vomiting or where a patient is coughing blood — its ascending action is unhelpful in active haemoptysis. Neither herb suits the cold, deficient cough with clear watery sputum. Above all, this is a two-herb prescription for a life-threatening infection: lung abscess and empyema require antibiotic treatment, chest imaging and often drainage; a sore throat with difficulty swallowing, drooling, a muffled voice, neck swelling or high fever needs same-day medical assessment.