One of the major adverse effects of Shakuyaku-kanzo-To (SKT),a herbal medicine containing licorice,is licoriceinduced pseudoaldosteronism with hypokalemia and hypertension.Owing to the risk of hypokalemia,caution should be therefore exercised when SKT is co-administered with potassium lowering drugs.In order to clarify this risk,we examined the occurrence of hypokalemia in 103 patients receiving SKT.Thirty (29.1%) of the 103 patients developed hypokalemia and SKT dosing periods tended to be longer in these patients than in those who did not develop hypokalemia (54.5 vs.23.0 days,respectively).The co-administration of potassium lowering drugs was more frequent in the patients with hypokalemia (90.0% vs.64.4% for no hypokalemia p<0.01).The occurrence rates of hypokalemia varied with drugs co-administered with SKT ; with 75.0% for glycyrrhizin preparations,47.2% for diuretics,41.9% for glucocorticoids,20.0% for sennoside preparations and 25.0% for others.
The above results confirmed that the co-administration of potassium lowering drugs enhanced SKT-induced hypokalemia.Frequent serum potassium monitoring is therefore required when potassium lowering drugs,especially glycyrrhizin preparations,diuretics and glucocorticoids,are co-administered to patients receiving SKT.
