Efficacy, Side Effects, and Monitoring of Oral Cyclosporine in Interstitial Cystitis-Bladder Pain Syndrome

Abstract

To evaluate the efficacy of oral cyclosporine A (CyA) in the treatment of refractory interstitial cystitis-bladder pain syndrome (IC-BPS) and to assess safety using drug level and renal function monitoring. Patients with IC-BPS who failed at least 2 prior treatments were enrolled in an open-label study of oral CyA. Medication was started at 3 mg/kg divided twice daily for 3 months. Dose was adjusted based on side effects and the drug level was measured 2 hours after the morning dose (C2). The primary end point was moderate or marked improvement of global response assessment or >50% improvement on the Interstitial Cystitis Symptom Index (ICSI) or Interstitial Cystitis Problem Index at 3 months. Twenty-two of 26 patients completed the 3-month follow-up; 18 completed the poststudy evaluation. The median symptom duration was 66 months (12-336). At 3 months, 31% (8/26) improved by global response assessment, 15% (4/26) had >50% improvement in the ICSI score, and 19% (5/26) had an improvement in the Interstitial Cystitis Problem Index score. Hunner lesions (HLs) predicted an improvement in the ICSI score (odds ratio = 15.4, 95% confidence interval: 1.7-224.6, P = .01), with 75% (3/4) of the responders having HL. Two patients withdrew because of hypertension or elevated serum glucose. The mean nuclear glomerular filtration rate declined at 3 months (98.9 ± 31.6 vs 84.2 ± 25.5 mL/min/1.73 m2, P = .01) and reversed to baseline after discontinuation of treatment. C2 levels did not correlate with symptoms but allowed dose reduction in 11 patients. Per American Urological Association guidelines, CyA can be effective in a proportion of patients with refractory IC-BPS. Patients with HL are more likely to benefit. Monitoring of C2 rather than trough levels can lead to dose reduction, thereby minimizing toxicity.