GAG layer replenishment therapy for chronic forms of cystitis with intravesical glycosaminoglycans--a review.

AIMS Glycosaminoglycan (GAG) layer replenishment is a cornerstone in the therapy of interstitial cystitis (IC). During the last years intravesical GAG layer replenishment has proven to be an effective treatment for overactive bladder (OAB), radiation cystitis, and recurrent urinary tract infections (UTIs). METHODS Examination of different substances available for intravesical GAG replenishment and evaluation of the evidence for the treatment of the above-mentioned conditions. RESULTS We searched the Medical Literature Analysis and Retrieval System Online (MEDLINE) database for studies on intravesical GAG replenishment. A total of 27 clinical studies remain relevant to this topic, many of them with mixed patient selection and suboptimal definition of symptom improvement/success. Two placebo controlled studies with hyaluronic acid failed to show superiority and have not been published. One active controlled randomized study has been published showing that chondroitin sulphate 0.2% has a clear benefit for OAB patients. Another study with chondroitin sulphate 2.0% failed to show statistically significant evidence, but was underpowered. CONCLUSIONS A short number of randomized controlled studies confirm efficacy of intravesical GAG layer replenishment therapy. Concluded from the study background (which comprises also uncontrolled studies), so far chondroitin sulphate 0.2% is in favor for intravesical GAG layer replenishment therapy. In general, large-scale trials are urgently needed to underline the benefit of this type of therapy.