BERKELEY, CA (UroToday.com) - Interstitial cystitis (IC) is a chronic and debilitating bladder syndrome primarily affecting women that is characterized by suprapubic pain associated with urinary urgency and frequency, and sterile, cytologically sterile urine. Treatment options have included hydrostatic distention, intravesical instillations (e.g. dimethyl sulfoxide or hyaluronic acid) or oral medication (e.g. anti-allergics or pentosan polysulfate), which at best had achieved brief, symptomatic relief.

Recently, a prospective, open label study to examine the safety and efficacy of the long-term administration of the tricyclic antidepressant amitriptyline in patients with interstitial cystitis was completed. The study was performed by A. Van Ophoven and L. Hertle from Munster, Germany and published in the November 2005 issue of the Journal of Urology.

A total of 94 patients were stratified into 2 groups, namely a National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) group who fulfilled NIDDK criteria for IC and a nonNIDDK group of those who presented with characteristic IC symptoms but met at least one NIDDK exclusion criterion. Amitriptyline was received strictly at bedtime following an established self-titration protocol without limitation of the maximum daily dose. Patients reporting improvement in a global response assessment (GRA) questionnaire were considered treatment responders. The GRA is a 7-point, centered scale rating overall well-being as markedly worse, moderately worse, slightly worse, no change, slightly improved, moderately improved and markedly improved. Further efficacy measures were changes in pain and urgency, functional bladder capacity and frequency. Changes in the O'Leary-Sant IC symptom and problem index (ICSI) (lowest symptom score 0 and highest 36) and rating of overall satisfaction with the therapeutic outcome were also reported. A closer look at the study population revealed a mean age of 52.9 years and mean symptom duration of 2.7 years. Fifty-nine patients met NIDDK criteria for IC and 35 patients comprised the nonNIDDK group. Mean follow-up was 19.0 months and mean treatment duration was 16.5 months.

Analysis of results showed an overall response to treatment in 60 patients (64%). No significant difference in the response rate in the 2 patient groups was observed. The overall mean dose of amitriptyline was 55 mg (range 12.5 to 150 mg). Anticholinergic and antimuscarinic side effects occurred in 79 patients (85%) with dry mouth being the most common at 79%. Certain symptoms improved dramatically compared to baseline, namely pain intensity (-22.1 mm on a 100 mm a visual analog scale (VAS)), urgency (-19.7 mm on a VAS), 24-hour frequency (-6.9 voids daily) and functional bladder volume (+32.9 ml). ICSI decreased by 7.9 points during treatment.

The results of this study suggest that long-term administration of amitriptyline is a feasible, safe and effective therapeutic approach for interstitial cystitis, resulting in a significant decrease in the various symptoms of the condition. While the anticholinergic side effects were significant, most patients were able to tolerate them with nighttime dosing.

J Urol. 2005 Nov; 174(5):1837-40