2023 Volume 19 Issue 1 Pages 50-55
When diagnosing refractory non-bacterial cystitis, drug-induced cystitis must be ruled out. We previously reported a case of allergic cystitis with delayed diagnosis caused by 8 years usage of Bofutsushosan. In this study, we conducted a literature review. We found 37 case reports (all from Japan) on cystitis induced by herbal medicine, including Kampo medicine, using the PubMed and JAMAS (Ichushi-Web) databases. The patient ages showed a bimodal distribution with peaks in childhood and old age (2-72, median 11). The ratio of male to female was 14 to 23. Sterile pyuria continued and cystoscopy showed severe inflammatory findings with occasional tumor-like masses. Bladder biopsy was done in 17 cases and 14 cases (82.4%) showed eosinophilic infiltration. The majority of causative Kampo drugs (94.6%) contained Scutellariae Radix (ogon) as a common ingredient. These drugs were used for chronic diseases such as bronchial asthma, atopic dermatitis, nephrosis syndrome, and hepatitis. The period of drug administration at the onset was 3 weeks to 10 years (median 2 years): 93.3% used Kampo drugs for more than 6 months before onset. Cystitis symptoms immediately disappeared after patients stopped using the drugs (3-42 days, median 10 days). Challenge tests (including unintended ones) were done in 12 cases which confirmed test-retest reliability without exception. Kampo medicine is widely used both as ethical drugs and OTC drugs in Japan. Therefore, physicians must be cautious about its adverse effects, especially allergic responses to ogon such as interstitial pneumonia, hepatic injury, and allergic cystitis.
