Randomized, double-blind, dose-ranging study of pentosan polysulfate sodium for interstitial cystitis.

OBJECTIVES: To compare the current recommended dose of pentosan polysulfate sodium (PPS) with doses two to three times higher. METHODS: We evaluated three dosages (300, 600, and 900 mg) of PPS in a randomized, double-blind, double-dummy, parallel-group, multicenter, 32-week study. Adults (n = 380) with a diagnosis of interstitial cystitis (IC) as determined by a positive cystoscopic examination combined with bladder pain and urgency or a history of IC symptoms for at least 6 months were enrolled. Participants completed the Patient's Overall Rating of Symptom Index (PORIS) and the O'Leary-Sant Interstitial Cystitis Symptom Index (ICSI) at baseline (ICSI only) and during follow-up visits at 4, 8, 12, 16, 24, and 32 weeks. RESULTS: Mean ICSI scores improved significantly during the 32 weeks for all dosages (baseline 11.2, 11.9, and 11.9 to endpoint 8.2, 8.1, 8.6 for 300, 600, and 900 mg, respectively; P <0.001) but the response to treatment was not dose dependent (no statistically significant difference in response among the three dosages). At baseline, 3.2%, 62.2%, and 34.6% reported mild, moderate, and severe symptoms, respectively, as assessed by the ICSI. At study end, 27.5%, 56.9%, and 15.7% reported mild, moderate, and severe symptoms, respectively. The PORIS scores improved within 4 weeks with 15.8% to 21.1% of all patients classified as responders (50% or greater improvement on PORIS). At 32 weeks, 49.6%, 49.6%, and 45.2% of all patients were responders at a dose of 300, 600, and 900 mg, respectively. Most adverse events were mild and resolved without intervention. CONCLUSIONS: For all three dosages of PPS, a clinically significant but similar response was demonstrated. The duration of therapy appears to be more important than the dosage.

Effect of pentosan polysulfate therapy on intravesical potassium sensitivity.

OBJECTIVES: To evaluate further the intravesical potassium sensitivity test (PST) as an indicator of the epithelial leak of interstitial cystitis (IC) and determine whether successful pentosan polysulfate (PPS; Elmiron) treatment is associated with a change in PST results. Most individuals with IC appear to have an abnormally permeable epithelium that allows urinary solutes such as potassium to penetrate to the bladder interstitium, provoking symptoms. METHODS: Data were from an optimal dose trial of PPS in IC. Patients underwent a PST before and after a 32-week trial of 300, 600, or 900 mg PPS/day. The response to PPS treatment was measured using the Patient Overall Rating of Improvement in Symptoms scale. The before and after treatment PSTs and Patient Overall Rating of Improvement of Symptoms scores were compared. RESULTS: Of 377 patients with IC at 28 centers, 302 (80%) had a positive PST at entry. Of the 198 patients who completed the study, 153 were PST positive at entry and 92 (60%) showed clinical improvement at exit. Clinically improved patients had significant improvement on the PST analog pain and urgency scales (3.2 to 1.3 and 3.6 to 1.9, respectively; P <0.0001). In contrast, patients with no clinical improvement had no significant change in pain (3.1 to 2.7) or urgency (3.6 to 3.2). CONCLUSIONS: PST shows abnormal epithelial permeability in most patients with IC and a significant reduction in this permeability after successful PPS therapy. PST appears to be a valid indicator of epithelial abnormality and a reliable test in the diagnosis of IC.