Time to initiation of pentosan polysulfate sodium treatment after interstitial cystitis diagnosis: effect on symptom improvement

Abstract

Objectives: Interstitial cystitis (IC) is a chronic, debilitating condition that is often associated with late diagnosis and a delay in initiation of appropriate IC-specific therapy. The purpose of this study was to determine whether the length of time from initial diagnosis to start of treatment impacts subsequent symptom improvement.

Methods: A retrospective analysis was conducted in 128 patients with IC who had been treated with pentosan polysulfate sodium (PPS) 300 mg/day for 32 weeks in a multicenter, randomized, double-blind, parallel-group clinical trial. Outcome measures included the O'Leary-Sant Interstitial Cystitis Symptom Index (ICSI) and the O'Leary-Sant Interstitial Cystitis Problem Index (ICPI). Early treatment was defined as treatment initiation 6 months or less after IC diagnosis, whereas late treatment was defined as treatment initiation 24 months or more after IC diagnosis. Efficacy data were analyzed by using the intent-to-treat, last-observation-carried-forward population.

Results: At the end of the study, mean changes from baseline in total ICSI and ICPI scores (+/- SEM) for early treatment (6 months or less) versus late treatment (24 months or more) were 3.97 +/- 0.59 versus 2.15 +/- 0.70 (P = 0.0472) and 3.94 +/- 0.56 versus 1.77 +/- 0.63 (P = 0.0117), respectively. Similar trends for both measures were observed when examining other times from IC diagnosis (3 months or less versus 24 months or more, 3 months or less versus 36 months or more, and 6 months or less versus 36 months or more).

Conclusions: Initiation of PPS treatment within 6 months of establishing the diagnosis of IC may be associated with greater improvement in patient symptoms and symptom bother.