RESUMEN
We report a case of drug-induced cystitis caused by the administration of two different Kampo medicines containing Scutellariae radix. The patient was prescribed bofutsushosan for weight gain at the age of 55. She visited her primary care physician approximately one month later for micturition pain and other symptoms, and was prescribed antibacterial agents based on a diagnosis of bacterial cystitis. The patient’s symptoms persisted even after she was treated for one month ; therefore, she was referred to the urology department of a general hospital. All medicines including Kampo medicines were discontinued ; her subjective symptoms and urinary findings improved within 2 weeks. Her symptoms of cystitis flared up after a few days of re-administration of bofutsushosan. Four months later, she developed cystitis-like symptoms again after using nyoshinsan for menopausal symptoms. Based on the aforementioned clinical observations, she was diagnosed with drug-induced cystitis due to bofutsushosan and nyoshinsan administration. The components of these two Kampo medicines and past history of Kampo medicine use were reviewed and Scutellariae radix was considered to be the causative agent. Drug-induced cystitis caused by herbal medicines generally takes a long time to develop, and symptoms resolve within a relatively short period following discontinuation of the causative agent. Several reports in the literature implicate Scutellariae radix as the etiological agent in such cases. We believe that it is necessary to pay close attention to the risk of cystitis in patients receiving long-term Kampo therapy.