The absorption of pirarubicin instilled intravesically immediately after transurethral resection of superficial bladder cancer

Objectives To assess the validity of the prophylactic use of pirarubicin ([2'R]-4-O-tetrahydropyranyl-doxorubicin) immediately after transurethral resection of bladder tumour (TURBT), using pharmacodynamic studies. Patients and methods The study included 20 consecutive patients with superficial bladder cancer. Pirarubicin (30 mg/50 mL or 30 mg/100 mL, 10 patients each) was instilled immediately after TURBT and retained in the bladder for 1 h. Blood samples were obtained before and at 15, 30, 60 and 120 min after the instillation. After retaining the drug for 1 h all the intravesical fluid was collected and assayed for pirarubicin. Results The plasma pirarubicin concentration in those receiving either dose was below detectable levels at any time after instillation. The mean recovery rate of pirarubicin in the drained fluid was 73%. Conclusion The intravesical instillation of pirarubicin immediately after TURBT caused no detectable plasma concentration and few systemic side-effects.