Liquorice-induced hypokalaemia in patients treated with Yokukansan preparations: identification of the risk factors in a retrospective cohort study

Objective To evaluate serum potassium levels and rates of hypokalaemia in patients treated with liquorice-containing Japanese traditional Kampo-medicines Yokukansan (YK) and Yokukansan-ka-chinpihange (YKCH). Design Retrospective cohort study. Setting Patients receiving YK preparations for dementia and other psychiatric disorders in the University of Tsukuba Hospital in Japan. Participants 389 patients (male/female: 174/215, 68.6±16.1 years) were treated with YK preparations for 231 days (range 6–2788 days). Patients whose potassium levels were Main outcome measure The occurrence rate of hypokalaemia and assessment of the risk factors for YK preparation-induced hypokalaemia. Results Of the 389 patients treated with YK preparations, 94 (24.2%) developed hypokalaemia (potassium levels Conclusions Serum potassium monitoring should be done at least monthly in patients with the following risk factors: LPID co-administration, YK administration, hypoalbuminaemia, and full dosage administration.