Efficacy of daily low-dose sildenafil for treating interstitial cystitis: results of a randomized, double-blind, placebo-controlled trial--treatment of interstitial cystitis/painful bladder syndrome with low-dose sildenafil

Objective: To evaluate the efficacy of daily low-dose sildenafil for the treatment of nonulcer interstitial cystitis (IC) in women.

Patients and methods: Forty-eight women with a clinical diagnosis of IC from 3 medical centers were randomly assigned to treatment with daily low-dose sildenafil (25 mg, n=24) or placebo (n=24) for 3 months. The O'Leary-Sant IC symptom and problem indices, visual analog scale scores, and a micturition diary with the interval of micturition, the frequency of nocturia, and urgency episodes were recorded before treatment, every 2 weeks after the treatment until 3 months. Patient Overall Rating of Improvement in Symptoms was assessed and regarded as effective when the value was above 50%.

Results: The IC symptom and problem indices scores and urodynamic index were significantly improved in sildenafil treatment group as compared with placebo group and baselines at week 4, 6, 8, 10, and 12, as well as 3 months after treatment (P<.05). Urodynamic index including first desire to void, strong desire to void, and maximum cystometric capacity was significantly improved in sildenafil treatment group at week 12 and at 3 months after treatment (P<.05). The efficiency of treatment reached 62.5%. However, no significant change of the visual analog scale values was observed between 2 groups except at week 12 in the sildenafil treatment group (P<.05). All adverse events were mild to moderate and transient.

Conclusion: Daily low-dose sildenafil is an easy, well-tolerated, and effective treatment for IC in women.