The use of Kampo medications that may cause heart failure in hospitalized acute heart failure patients in a Japanese hospital

BACKGROUND: The use of Kampo medications (Japanese traditional herbal medications) is common in Japan. However, some Kampo medications may cause heart failure. Given that the incidence of heart failure has increased in past decades, investigating the prevalence of the use of Kampo medications that may cause heart failure in patients with acute heart failure is important. METHOD: A retrospective cross‐sectional study was conducted. All 437 consecutive hospitalized patients with acute heart failure from April 2017 to October 2019 were included. The primary outcome was the use of Kampo medications, including ephedra, licorice, aconite, or ginseng, which were defined as those that may cause heart failure. The causality between these medications and the index of acute heart failure was determined by clinical pharmacists based on the Naranjo criteria. RESULTS: The mean patient age was 81.1 years old, and 199 (54.5%) were women. Kampo medications that may cause heart failure were used in 30 patients (6.9%), and in four of these patients, acute heart failure was judged to be caused by Kampo medications. In the multivariable analysis, the number of non‐Kampo medications used regularly (OR 1.13) and female sex (OR 2.23) were the only independent predictive factors for the use of Kampo medications that may cause heart failure. CONCLUSIONS: A substantial proportion of acute heart failure patients in Japanese hospitals use Kampo medications that may cause heart failure. Further study is warranted to investigate the causal link between the incidence of acute heart failure and the use of these herbal medications.