Efficacy of Clorpactin in refractory bladder pain syndrome/interstitial cystitis: a randomized controlled trial.

Introduction: Clorpactin is an antibacterial agent with limited evidence for its use as instillation therapy in patients with bladder pain syndrome/interstitial cystitis (BPS/IC). This was a multi-centre, single-blinded randomized controlled trial to investigate whether Clorpactin instillation results in symptom improvement in patients with refractory BPS/IC.

Methods: Fifty women with refractory BPS/IC were randomized to undergo cystoscopy/hydrodistension (25) or instillation of Clorpactin 0.4% solution (25) under general anaesthesia. Primary outcome was based on Global Response Assessment (GRA) at 3 months; secondary outcomes were based on O'Leary Sant Symptom (OLSI) and Problem (OLPI) questionnaire scores, visual analogue scale (VAS) score for pain and bladder diary parameters.

Results: Complete follow-up data were available on 22 in the hydrodistension group and 16 in the Clorpactin group. GRA improvement was 4.5% for hydrodistension and 56% for Clorpactin (p = 0.001) at 3 months. Reduction in mean total scores for OLSI (14.1 to 9.1; p = 0.004) and OLPI (12.6 to 7.4; p = 0.001) was seen in the Clorpactin group only. VAS pain scores were reduced in the Clorpactin group only (7.4 to 3.3; p < 0.001). Post-treatment VAS pain scores did not differ between groups although 6/25 (24%) women in the Clorpactin group required admission for pain compared to 1/25 (4%) in the hydrodistension group.

Conclusions: Clorpactin treatment results in significant improvement in BPS/IC symptoms, bother and pain based on the GRA, OLSI/OLPI and VAS pain scores at 3 months post-treatment compared to cystoscopy/hydrodistension. These conclusions are limited by the high loss to follow-up in both groups.