Intravesical hyaluronic acid in the treatment of refractory interstitial cystitis

Purpose: Based on the assumption that interstitial cystitis results from a defective mucous lining of the bladder epithelium, we investigated the activity of hyaluronic acid in the treatment of this disease. Hyaluronic acid is an important glycosaminoglycan present in all connective tissues, including the glycosaminoglycan layer of the vesical mucosa. It exhibits a variety of pharmacological properties that enhance its appeal for the therapy of interstitial cystitis. Materials and Methods: A total of 25 patients with characteristic findings of interstitial cystitis refractory to other medical treatments participated in a trial of intravesical hyaluronic acid at a dose of 40 mg. weekly for 4 weeks and then monthly. Response to therapy was evaluated by symptom score, voiding diaries and visual analog scales. Results: An initial 56% positive (complete plus partial) response rate at week 4 increased to 71% by week 12 and response was maintained until week 20. Beyond week 24 there was a moderate decrease in the effectiveness of the medication. There was no significant toxicity attributable to hyaluronic acid in the bladder. Conclusions: The response of patients with refractory interstitial cystitis to the intravesical administration of hyaluronic acid was gratifying. In the past many therapies for interstitial cystitis which were initially considered promising failed the test of a controlled study. Such a study to determine the activity of hyaluronic acid in patients with interstitial cystitis is currently under way.