Absorption of epirubicin instilled intravesically immediately after transurethral resection of superficial bladder cancer

As postoperative adjuvant therapy for superficial bladder cancer, intravesical instillation therapy is commonly conducted. In this case, from the view point of prevention of intraoperative dissemination, commencement of instillation therapy at an early postoperative period is preferred. However, increased drug permeability is suspected because of damage to the bladder mucosa during operation. Therefore, this study was conducted to investigate the plasma level of epirubicin (EPI) instilled immediately after transurethral operation. EPI (20 mg/40 ml or 50 mg/100 ml) was instilled immediately after a transurethral operation, and retained in the bladder for 1 h. Blood samples were obtained before instillation, as well as 30, 60, 120 and 240 min after instillation, and EPI levels were assayed. The mean EPI concentrations (ng/ml) among the 20-mg/40 ml group (n = 5) were <2.5 and <2.0 at 30 and 60 min, respectively, after which they were undetectable. The 50-mg/100 ml group (n = 5) recorded 5.0, 4.4 and <3.0 after 30, 60 and 120 min, respectively, and after 240 min it was undetectable. Intravesical instillation of EPI immediately after a transurethral operation causes a small increase in the plasma level and it is thought to cause small systemic side effects.