Compatibility of hypokalaemia caused by low-dose prednisolone plus abiraterone acetate therapy for metastatic castration-resistant prostate cancer.

Background: This study aimed to investigate the relationship between low-dose prednisolone (PSL) and the incidence of hypokalaemia at abiraterone acetate (abiraterone) plus PSL combination therapy targeting Japanese patients with metastatic castration-resistant prostate cancer (mCRPC).

Methods: This retrospective observational study included 153 Japanese patients treated with abiraterone and PSL for mCRPC at Kariya Toyota General Hospital and Gifu General Medical Center between September 2014 and October 2022. The incidence of grade ≥ 2 hypokalaemia as well as serum potassium level variations and the continuous combination therapy duration were compared between the low-dose (5 mg/day of PSL) and the standard-dose (10 mg/day of PSL) groups.